Is it taken up by chef in kitchen? (5)
I believe the answer is:
'is it taken up' is the definition.
I can't tell whether this definition defines the answer.
'chef in kitchen?' is the wordplay.
'KNIFE' is hidden back-to-front within the letters.
However, I'm uncertain how the hidden word is indicated.
'by' is the link.
(Other definitions for knife that I've seen before include "Piece of cutlery" , "Cutting blade" , "Dagger" , "Potential weapon" , "Attack" .)