Let slip of a girl eat both bananas (4,3,4)
I believe the answer is:
miss the boat
'let slip' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'girl eat both bananas' is the wordplay.
'girl' becomes 'miss' (term of address for an unmarried woman).
'bananas' indicates an anagram (bananas can informally mean crazy).
'eat'+'both'='eatboth'
'eatboth' is an anagram of 'theboat'.
'miss'+'theboat'='MISS THE BOAT'
'of a' acts as a link.
Can you help me to learn more?
(Other definitions for miss the boat that I've seen before include "as tardy tars may do" , "Fail to take chance" , "fire shot across bows, say" , "and not get the next answer [THREE DECKER]?" , "Fail through lateness" .)