Definition of "punter"

punter

/ˈpʌn.tə(ɹ)/

noun
plural punters
1. One who bets (punts) against the bank.
2. One who oars or poles a punt (pontoon).
3. One who punts a football.
4. (Australia, UK, New Zealand, slang) One who gambles. See speculator.
  Quotations
  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—[...].
  1964 June, Cecil J. Allen, “Locomotive Running Past and Present”, in Modern Railways, page 387
5. (Britain, Australia, slang) A customer of a commercial establishment, frequently of a pub or (alternatively) of a prostitute.
  Quotations
  Everybody knows your mum is a whore / Getting 'round Piccadilly looking for willy / Punters pull up and say "don't be silly"
  2016 March 7, “Road Rage (Freestyle)”, performed by Little T (Josh Tate)
6. (climbing) A beginner or unskilled climber.
7. The person who keeps score in basset or ombre.
8. (Scotland) A person who trades with a gang but is not a gang member.
  Quotations
  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.
  2013, James Patrick, A Glasgow Gang Observed
9. (Internet slang) A program used to forcibly disconnect another user from a chat room.
  Quotations
  Punters generate hundreds of information inquiries to a legitimate user's client, such as invitations to chat. […] The user is punted from the channel, and must rejoin to gain access.
  2001, Roger A. Grimes, Malicious Mobile Code: Virus Protection for Windows, page 236