Small fruit put underground, by the sound of it (5)
I believe the answer is:
berry
'small fruit' is the definition.
(I've seen this before)
'put underground by the sound of it' is the wordplay.
'put underground' becomes 'bury' (I've seen this before).
'by the sound of it' shows a homophone (sound like).
'bury' sounds like 'BERRY'.
(Other definitions for berry that I've seen before include "Small succulent fruit" , "Smal pulpy fruit" , "Word linking black or blue" , "Small juicy fruit" , "Pulpy edible fruit" .)