Is a hen up early? (5)
I believe the answer is:
layer
'is a hen' is the definition.
(I've seen this before)
'up early?' is the wordplay.
'up' is an anagram indicator (letters get chucked up).
'early' with letters rearranged gives 'LAYER'.
(Other definitions for layer that I've seen before include "Coating" , "Single thickness, tier" , "Tier or thickness - or a hen?" , "Single thickness and hen" , "Source of eggs" .)