Wicked piece of radish one's tasted (9)
I believe the answer is:
dishonest
'wicked' is the definition.
(dishonest can mean wicked or corrupt)
'piece of radish one's tasted' is the wordplay.
'piece of' indicates the answer is hidden within the clue.
'DISHONEST' can be found hidden inside 'radish ones tasted'.
(Other definitions for dishonest that I've seen before include "Not trustworthy" , "Untruthful - mendacious" , "Deceitful - hedonists (anag)" , "Corrupt" , "shady" .)