If chewed, sole can taste very astringent! (4)
I believe the answer is:
sloe
'taste very astringent' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'if chewed sole' is the wordplay.
'if chewed' indicates an anagram.
'sole' anagrammed gives 'SLOE'.
'can' is the link.
Can you help me to learn more?
(Other definitions for sloe that I've seen before include "Sour blackthorn fruit" , "Fruit steeped in gin to make a liqueur" , "Wild plum" , "Sour blue-black fruit" , "Musical study" .)