Powerful pressure on a French chap of good standing? (7)
I believe the answer is:
pungent
'powerful' is the definition.
'pressure on a french chap of good standing?' is the wordplay.
'pressure' becomes 'p' (abbreviation).
'on' means one lot of letters go next to another.
'a french' becomes 'un' ('a' in French).
'chap of good standing?' becomes 'gent' (a gentleman).
'p'+'un'+'gent'='PUNGENT'
(Other definitions for pungent that I've seen before include "Sharply tasting or smelling" , "Acrid; sarcastic (humour)" , "With a fifteen ac smell/taste" , "Acrid to smell" , "Offensive" .)