Slippery part of a banana (4)
I believe the answer is:
peel
'slippery part of a banana' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for peel that I've seen before include "Remove skin of vegetable or fruit" , "zest, getting out of this scrape?" , "island" , "Take skin off fruit" , "Lemon skin" .)