Fruit place underground, say (5)
I believe the answer is:
berry
'fruit' is the definition.
(I know that berry is a type of fruit)
'place underground say' is the wordplay.
'place underground' becomes 'bury' (I've seen this in another clue).
'say' indicates a 'sounds like' (homophone) clue.
'bury' is a homophone of 'BERRY'.
(Other definitions for berry that I've seen before include "Pulpy edible fruit" , "Word linking black or blue" , "Romeo's family" , "Small round stoneless fruit, may be black (5)" , "Smal pulpy fruit" .)