Fruit in slippery gunk, initially wiped (4)
I believe the answer is:
lime
'fruit' is the definition.
(lime is a kind of fruit)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for lime that I've seen before include "Caustic calcium" , "Green fruit -- green colour" , "Having no money" , "Tree, linden or citrus" , "Bright light green" .)