Part of the next layer? (3)
I believe the answer is:
hen
'layer?' is the definition.
(hens lay eggs)
'part of the next' is the wordplay.
'part of' indicates a hidden word.
'HEN' can be found hidden inside 'the next'.
(Other definitions for hen that I've seen before include "Insufficient in amount" , "Female bird" , "Adult female chicken" , "This party is for women only" , "Domestic egg layer" .)