Early evening (5)
I believe the answer is:
seven
'early evening' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for seven that I've seen before include "Number (of stars in the sky?)" , "Number of colours of the rainbow" , "Number of Wonders of the World" , "Number of sins, seas or dwarves" , "Numeral" .)