Be inclined at some suitable angle (4)
I believe the answer is:
lean
'be inclined' is the definition.
('lean' can be a synonym of 'be inclined')
'some suitable angle' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'LEAN' is hidden in the letters of 'suitable angle'.
'at' acts as a link.
(Other definitions for lean that I've seen before include "With no fat; slope" , "Thin; heel" , "without success" , "Slight - incline" , "Incline, bend" .)