Definition from Wiktionary, the free dictionary
wanker (plural wankers)
- A person who wanks.
- (UK, Australia, New Zealand, slang, pejorative) An idiot, a stupid, annoying or ineffectual person.
- (UK, Australia, New Zealand, slang, pejorative) Someone who shows off too much, a poser or poseur; someone who is overly self-satisfied.
- (UK, Australia, New Zealand, slang, humorous, vulgar) A very informal address used between friends.
Usage notes 
- Used mainly of males.
- (person who wanks): masturbator, onanist, pickle tickler
Derived terms 
person who wanks
to be checked