Allow male to enter mine entrance (5)
I believe the answer is:
admit
'allow' is the definition.
(admit can mean to allow or accept)
'male to enter mine entrance' is the wordplay.
'male' becomes 'm' (common abbreviation).
'to enter' indicates putting letters inside.
'mine entrance' becomes 'adit' (an adit is a passage leading to a mine).
'm' inserted into 'adit' is 'ADMIT'.
(Other definitions for admit that I've seen before include "receive" , "Come clean" , "Take on" , "permit to come in" , "Reveal" .)