Carry on business - with a knife? (7)
I believe the answer is:
operate
'carry on business' is the definition.
(I've seen this before)
'a knife?' is the wordplay.
I cannot quite see how this works, but
'a' could be 'per' (eg 'one a day' means 'one per day') and 'per' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'with' acts as a link.
Can you help me to learn more?
(Other definitions for operate that I've seen before include "Carry out surgery" , "Carry on business" , "Perform surgery or run a machine" , "Eat rope (anag.)" , "Work, run" .)