Is probing male's first and foremost injury (8)
I believe the answer is:
mischief
'injury' is the definition.
(thesaurus)
'is probing male's first and foremost' is the wordplay.
'probing' is an insertion indicator (probe can mean to make a hole in).
'male' becomes 'm' (common abbreviation).
'first and foremost' becomes 'chief'.
'm'+'chief'='mchief'
'is' placed inside 'mchief' is 'MISCHIEF'.
(Other definitions for mischief that I've seen before include "Monkey business" , "Black . . . . . . . . (Evelyn Waugh)" , "Naughtiness, trouble" , "Devilment, roguishness" , "Naughtiness, devilment" .)