Animals kept in shape somehow (4)
I believe the answer is:
apes
'animals' is the definition.
(ape is a kind of animal)
'kept in shape somehow' is the wordplay.
'kept in' says the answer is hidden in the clue.
'APES' can be found hidden inside 'shape somehow'.
(Other definitions for apes that I've seen before include "Zoo animals" , "Imitates like primates" , "Mimics like primates" , "Large primates" , "Parrots" .)