Gin that is drunk very late (2,5)
I believe the answer is:
at night
'very late' is the definition.
(late in the day)
'gin that is drunk' is the wordplay.
'is drunk' indicates anagramming the letters.
'gin'+'that'='ginthat'
'ginthat' with letters rearranged gives 'AT NIGHT'.
(Other definitions for at night that I've seen before include "''Red sky . . . . . . ., shepherd's delight'' (2, 5)" , "'Red sky ......., shepard's delight'" .)