Unprofitable bank (4)
I believe the answer is:
lean
I believe this clue is a double definition.
'unprofitable' is the first definition.
(similar in meaning)
'bank' is the second definition.
(bank can mean to lean or tilt)
(Other definitions for lean that I've seen before include "Incline; (of person) thin" , "Thin; rest (against)" , "Slim; veer" , "Slant" , "Of meat, with little or no fat" .)