A professional attitude not entirely suitable (7)
I believe the answer is:
apropos
'suitable' is the definition.
(apropos means appropriate or pertinent)
'a professional attitude not entirely' is the wordplay.
'professional' becomes 'pro' (abbreviation).
'attitude' becomes 'pose' (attitude can mean a pose or stance).
'not entirely' means to remove the last letter (not all of the word).
'pose' with its last letter taken away is 'pos'.
'a'+'pro'+'pos'='APROPOS'
(Other definitions for apropos that I've seen before include "In respect of" , "As regards" , "Concerned with" , "Suitable; to the point" , "Regarding" .)