Synonyms for Wanker:

n.

public nuisance, know-all, yob, vermin, loudmouth, (the) scum of the earth, creep, horror, public enemy number one. wanker (noun)
jerk off, tosser.

Other synonyms:

jerk-off
jerk off.
Other relevant words:
loudmouth, know-all, vermin, creep, horror, yob.