Green’s Dictionary of Slang

wank adj.

also wanko

a general pej.; unpleasant, distasteful, useless, etc.

[UK]Fraser & Meadows TwentyFourSeven [film script] (1998) 8: The Lads laugh and walk away, leaving Benny with a red eye and the other Lads feeling pretty useless and wank.
[UK]Guardian Rev. 28 Jan. 13: Forget the wanko-arty, terminally indecisive title Untitled.
[US]C. Buzzell My War (2006) 11: A couple of wank community-college here and there, like photography and computers 101.

In derivatives

wank-faced (adj.)

a general derog. description.

[UK]Guardian Weekend 15 Jan. 27: A ‘wank-faced Tory twat police lackey cunt.’.