punter

1. (UK, Ireland, Commonwealth, slang) One who gambles or bets.Examples: "[…] and having only peeped into a play-room at Baden-Baden when he hung on Dobbin's arm, and where, of course, he was not permitted to gamble, came eagerly to this part of the entertainment and hankered round the tables where the croupiers and the punters were at work."; "By Savernake the train was 4½min early; we then had the thrill of sweeping through Newbury at 95 m.p.h.—and one wonders if any of the punters on the neighbouring racecourse had any eyes for our flying cavalcade as we swept by, for it was a race day—[…]."; "Punters know the house usually wins, but most have no idea that bookies sharpen their edge via something called “stake factoring”, the process by which winning customers are dialled down, while losers are allowed to bet more."CommonwealthIrelandUKslang

2. (UK, Ireland, Commonwealth, slang) A customer of a commercial establishment, frequently of a pub or (alternatively) of a prostitute.Examples: "She's working the streets like she does every night / Pulling in punters left and right"; "Everybody knows your mum is a whore / Getting 'round Piccadilly looking for willy / Punters pull up and say "don't be silly""; "The number of UK pubs is falling and there is less consensus about how punters should behave. Here’s a guide to getting the most out of a trip to the boozer[.]"Synonyms: pubgoer, pubber, ;, all-nighter, curb crawler, fare, gonk, janeCommonwealthIrelandUKslang

3. (climbing) A beginner or unskilled climber.

4. (Scotland) A person who trades with a gang but is not a gang member.Examples: "He had stolen 'trannies' (transistor radios) and hub caps from cars outside the main hotels in Glasgow, turning the collection into money through dealing with a 'punter' at Charing Cross."Scotland