Nearly time for evening (5)
I believe the answer is:
night
'evening' is the definition.
(I've seen this before)
'nearly time' is the wordplay.
'nearly' becomes 'nigh' (synonyms).
'time' becomes 't' (abbreviation).
'nigh'+'t'='NIGHT'
'for' acts as a link.
(Other definitions for night that I've seen before include "Time of darkness" , "Period of darkness" , "For most, the time for sleep" , "'She walks in beauty, like the . . . . .' (Byron)" , "Day's partner" .)