Glossary of betting and gambling terms

By The Casino Deals team · Updated 15 October 2026 · 3 min read

This glossary of betting and gambling terms explains, in plain English, the words you’ll meet on our deal pages, casino reviews and guides. It covers casino games, bonuses, sports betting and safer gambling, from accumulators to the green zero. There are 89 terms below, so use the letters to jump straight to the one you need.

Betting and gambling terms from A to Z

Gambling has its own language, and offer terms can be hard to follow. So each entry below gives a short, jargon-free definition. Where a term matters for a welcome offer, such as wagering requirements or max win caps, we also explain the catch. For the basics, read our online casino basics and sports betting basics guides, or try casino games for free.

A

Acca insurance: A bookmaker offer that refunds your stake, usually as a free bet, if just one leg of your accumulator lets you down.
Accumulator (acca): One bet that combines several selections. Every selection must win for the bet to pay out, but the odds multiply, so the potential return is much bigger than a single bet.
Ante-post: A bet placed well before an event, often days or weeks ahead. The odds can be bigger, but you usually lose your stake if your pick doesn't take part.
Asian handicap: A football market that gives one team a head start of goals (including half or quarter goals). It removes the draw, so there are only two outcomes.
Auto-play: A slot setting that spins the reels automatically for a set number of rounds. UK rules now limit features like this to keep play under control.

B

Banker: In baccarat, one of the two hands you can bet on. In betting, it's also slang for a selection you feel very confident about.
Bankroll: The money you've set aside for gambling. Keeping it separate from everyday spending helps you stay in control.
Bet builder: A single bet that combines several outcomes from the same match, such as the result, goalscorer and number of corners.
BOG (best odds guaranteed): A horse racing offer: if the starting price is bigger than the odds you took, the bookmaker pays you at the bigger price.
Bonus buy: A slot feature that lets you pay to go straight to the bonus round. Bonus buys are banned at UK-licensed casinos.
Bonus funds: Money credited by a casino as part of an offer. Unlike cash, it usually has to be wagered before any winnings can be withdrawn.
Burn card: In card games such as blackjack, a card taken from the top of the shoe and put aside without being played.

C

Cashback: An offer that returns a share of your losses, either as cash or as bonus funds. Check whether the cashback itself carries wagering.
Cash out: A feature that lets you settle a bet before the event finishes, for an amount the bookmaker offers at that moment.
Casino chips: Tokens used to place bets at table games. Online, they're simply the on-screen stakes you click to bet.
Cluster pays: A slot payout system where you win by landing groups of matching symbols that touch, rather than lines from left to right.
Cooling-off period: A short break from gambling that you can set on your account, usually from 24 hours up to six weeks.
Croupier (dealer): The person who runs a table game, such as roulette or blackjack. Live casino games stream real croupiers from a studio.

D

Decimal odds: Odds shown as a single number, such as 3.00. Multiply your stake by the odds to see your total return, including your stake.
Demo mode: A free version of a casino game played with virtual credits. It's a good way to learn how a game works without spending money.
Deposit limit: A cap you set on how much you can deposit each day, week or month. Every UK-licensed casino must offer one.
Double down: A blackjack move where you double your stake in return for exactly one more card.

E

Each way: Two equal bets: one for your pick to win and one for it to place. A £5 each-way bet therefore costs £10.
Edge (house edge): The casino's built-in advantage on a game, shown as a percentage. It equals 100% minus the game's RTP.
Evens: Odds of 1/1 (2.00 in decimal). A winning £10 bet returns £20: your £10 stake plus £10 profit.
Exchange (betting exchange): A site where people bet against each other rather than against a bookmaker. You can back an outcome to happen or lay it not to.
Expiry: The time limit on an offer. Free spins, bonus funds and free bets all lapse if you don't use them in time.

F

Favourite: The selection with the shortest odds, meaning the bookmaker thinks it's the most likely winner.
Fractional odds: Traditional UK odds such as 5/2. You'd win £5 for every £2 staked, plus your stake back.
Free bet: A bet the bookmaker pays for. If it wins, you normally keep the winnings but not the free bet stake (stake not returned).
Free spins: Spins on a slot paid for by the casino, usually worth 10p each. Winnings may be paid as cash or as bonus funds.

G

Gambling Commission: The regulator for gambling in Great Britain. Every legal UK casino and bookmaker must hold its licence.
GAMSTOP: The free UK self-exclusion scheme. Signing up blocks you from every UK-licensed gambling site for six months, a year or five years.

H

Hit frequency: How often a slot pays out a win of any size. A 25% hit frequency means roughly one winning spin in four.

I

In-play: Betting while an event is already under way, with odds that update as the action unfolds.
Inside bets: Roulette bets on single numbers or small groups, such as a straight, split, street or corner. They pay more but win less often.

J

Jackpot: The top prize on a game. Progressive jackpots grow as players stake and can reach millions.

K

KYC (know your customer): The identity, age and address checks a casino must complete. UK sites must verify you before you can deposit or play.

L

Lay bet: On an exchange, a bet that something will not happen. You act as the bookmaker for another customer's back bet.
Licence: The permission a gambling operator needs to trade legally. In Great Britain this comes from the Gambling Commission.
Live casino: Real table games such as roulette, blackjack and game shows, streamed live from a studio with real dealers.
Low volatility: Slots that pay small wins often. Your balance moves gently, but big wins are rare.

M

Matched betting: Using free bets from bookmakers and covering every outcome on an exchange to lock in a small profit from the offers.
Max bet rule: A limit on how much you can stake per spin or bet while using bonus funds. Breaking it can void your winnings.
Max win cap: The most you can win from a bonus or set of free spins. Anything above the cap is removed.
Megaways: A slot mechanic where the number of symbols on each reel changes every spin, giving thousands of ways to win.
Minimum odds: The lowest odds a qualifying bet must have for an offer to count, for example 1/2 (1.50).
Multiplier: A feature that multiplies a win, for example ×2 or ×10. Common in slot bonus rounds and game shows.

N

Natural (blackjack): An ace and a ten-value card as your first two cards. It usually pays 3 to 2.
No deposit bonus: A small bonus you get just for signing up, without putting money in. It almost always has strict limits.
No wagering: An offer where winnings are paid as real cash that you can withdraw straight away.

O

Odds against: Odds where the profit is bigger than the stake, such as 3/1. The outcome is thought less likely than not.
Odds on: Odds where the profit is smaller than the stake, such as 1/2. The outcome is thought more likely than not.
Opt in: Actively choosing to join an offer, usually with a button or tick box. Some offers don't count unless you opt in first.
Outside bets: Roulette bets on large groups of numbers, such as red or black, odd or even, or high or low. They win often but pay less.

P

Pay by mobile: A deposit method that adds the payment to your phone bill. It usually has low limits and can't be used for withdrawals.
Paylines: The lines across a slot's reels where matching symbols must land to win.
Payout: The amount paid back on a winning bet or spin, including your stake.
Place terms: In each-way betting, the share of the win odds paid on the place part (often 1/4 or 1/5) and how many places count.
Player: In baccarat, one of the two hands you can bet on, alongside banker and tie.
Progressive jackpot: A jackpot that grows with every stake placed across a network of players until someone wins it.

Q

Qualifying bet: The bet you must place to unlock an offer, such as a free bet. It usually has minimum odds and a minimum stake.

R

Reality check: A reminder that pops up during play to show how long you've been playing and what you've spent.
Reel: A vertical column of symbols on a slot. Most slots have five reels.
Rollover: Another word for wagering requirements: how many times you must play bonus funds through before withdrawing.
RTP (return to player): The share of all money staked that a game pays back over the long run. 96% RTP means £96 back per £100 staked on average.
Rule 4: A deduction from horse racing winnings when a runner is withdrawn late, because the remaining horses' chances improve.

S

Safer gambling tools: Features that help you stay in control, such as deposit limits, time-outs, reality checks and self-exclusion.
Scatter: A slot symbol that pays or triggers a feature wherever it lands, not just on a payline.
Self-exclusion: Blocking yourself from gambling for a set period, either on one site or across all UK sites through GAMSTOP.
Shoe: The box that holds several decks of cards in blackjack and baccarat.
Single: A bet on one selection only. It's the simplest bet you can place.
Slot: A reel-based casino game where symbols are randomly drawn on each spin. Slots make up most online casino libraries.
Split: In blackjack, turning a pair into two separate hands. In roulette, a bet on two neighbouring numbers.
Stake: The amount of money you put on a bet or spin.
Stake limits: UK rules cap online slot stakes at £5 per spin for over-25s and £2 per spin for 18 to 24-year-olds.
Stand: Keeping your blackjack hand as it is, without taking another card.
Starting price (SP): The official odds of a horse or greyhound when the race starts.
Sticky bonus: Bonus funds that can't be withdrawn themselves; only the winnings above them can be cashed out.
Street: A roulette bet on a row of three numbers, such as 1, 2 and 3. It pays 11 to 1.

T

Time-out: A short break from your account, from 24 hours up to six weeks, set through the casino's safer gambling page.
Tote: Pool betting on horse racing, where stakes go into a pool and winners share it after a deduction.
Treble: An accumulator with three selections. All three must win.

V

Volatility (variance): How much a slot's results swing. High volatility means bigger but rarer wins; low volatility means small, frequent wins.

W

Wagering requirements: How many times you must play through bonus funds before you can withdraw them. Capped at 10x at UK-licensed casinos since 19 January 2026.
Welcome offer: The bonus a casino or bookmaker gives new customers for signing up and making a first deposit or bet.
Wild: A slot symbol that stands in for other symbols to complete a win.
Withdrawal: Taking money out of your account. UK sites must verify your identity first, and some methods are faster than others.

Z

Zero (green zero): The green pocket on a roulette wheel. It's the source of the house edge: European wheels have one zero, American wheels have two.

Betting and gambling terms from A to Z

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

V

W

Z

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