Something incisive in theatre use (7)
I believe the answer is:
scalpel
'use' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for scalpel that I've seen before include "Surgeon's blade" , "A surgeon's knife 97)" , "Surgical tool" , "Surgeon's instrument" , "Surgeon's tool" .)