What frogs do when they depart? (5)
I believe the answer is:
croak
'depart?' is the definition.
(thesaurus)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for croak that I've seen before include "Caw" , "Frog's call" , "Make a froggy sound" , "Noise from pond life - die" , "Frog's sound - die" .)