Animal that flies from abattoir (3)
I believe the answer is:
bat
'animal that flies' is the definition.
(bats fly)
'from abattoir' is the wordplay.
'from' says the answer is hidden in the clue.
'BAT' is hidden within 'abattoir'.
(Other definitions for bat that I've seen before include "Night flier" , "Small winged mammal, may be vampire" , "Cricket implement or flying mammal" , "Cricket, table-tennis and baseball implement" , "Cricketer; mammal" .)