Defeat inmate with short question (7)
I believe the answer is:
conquer
'defeat' is the definition.
(to conquer is to defeat or beat)
'inmate with short question' is the wordplay.
'inmate' becomes 'con' (convict).
'with' says to put letters next to each other.
'short' means to remove the last letter.
'question' becomes 'query' (synonyms).
'query' with its last letter taken away is 'quer'.
'con'+'quer'='CONQUER'
(Other definitions for conquer that I've seen before include "Overcome, vanquish" , "Overcome by force" , "worst" , "to follow William's example" , "Best" .)