Interrogate male about liberal pest, maybe (7)
I believe the answer is:
problem
'pest maybe' is the definition.
'interrogate male about liberal' is the wordplay.
'interrogate' becomes 'probe' (both can mean to question or investigate).
'male' becomes 'm' (common abbreviation).
'about' indicates putting letters inside.
'liberal' becomes 'l' (abbreviation).
'probe'+'m'='probem'
'probem' going around 'l' is 'PROBLEM'.
(Other definitions for problem that I've seen before include "Something to be solved" , "Snag" , "Trouble" , "Difficult matter to solve" , "Matter hard to cope with" .)