From WordNet (r) 3.0 (2006):
croak
n 1: a harsh hoarse utterance (as of a frog) [syn: croak,
croaking]
v 1: pass from physical life and lose all bodily attributes and
functions necessary to sustain life; "She died from
cancer"; "The children perished in the fire"; "The patient
went peacefully"; "The old guy kicked the bucket at the age
of 102" [syn: die, decease, perish, go, exit,
pass away, expire, pass, kick the bucket, cash in
one's chips, buy the farm, conk, give-up the ghost,
drop dead, pop off, choke, croak, snuff it] [ant:
be born]
2: utter a hoarse sound, like a raven [syn: croak, cronk]
3: make complaining remarks or noises under one's breath; "she
grumbles when she feels overworked" [syn: murmur, mutter,
grumble, croak, gnarl]