The end of the bread and butter, say (5)
I believe the answer is:
utter
'say' is the definition.
(to utter something is to speak or say it)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for utter that I've seen before include "Complete madman" , "issue" , "talk" , "Antique offer for sale" , "To say, articulate" .)