Frog's sound (5)
I believe the answer is:
croak
'frog's sound' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for croak that I've seen before include "Make a froggy sound" , "Caw" , "Frog's call" , "Noise from pond life - die" , "Frog's sound - die" .)