Cat taking head off part of flower (6)
I believe the answer is:
anther
'part of flower' is the definition.
('anther' is part of 'flower')
'cat taking head off' is the wordplay.
'cat' becomes 'panther' (panther is a kind of cat).
'taking head off' means to remove the first letter.
'panther' with its first letter taken off is 'ANTHER'.
(Other definitions for anther that I've seen before include "produces pollen" , "(Actors) leave stage" , "Part of a flower's stamen that contains pollen" , "Pollen-holding part of stamen" , "Part of a plant that contains pollen" .)