Close for the evening mostly (4)
I believe the answer is:
nigh
'close' is the definition.
('nigh' can be similar in meaning to 'close')
'the evening mostly' is the wordplay.
'the evening' becomes 'night' (I've seen this before).
'mostly' means to remove the last letter.
'night' with its final letter removed is 'NIGH'.
'for' is the link.
(Other definitions for nigh that I've seen before include "Near, as in archaic usage" , "Almost (arch.)" , "Just round the corner" , "All but one" , "in the vicinity?" .)