croak vs predecease

croak is a noun but predecease is not a noun.

Word	Noun	Adjective	Verb	Adverb
croak	Yes	No	Yes	No
predecease	No	No	Yes	No

As verbs, predecease is a hyponym of croak; that is, predecease is a word with a more specific, narrower meaning than croak:

croak: pass from physical life and lose all bodily attributes and functions necessary to sustain life
predecease: die before; die earlier than

Other hyponyms of croak include abort, asphyxiate, stifle, suffocate, buy it, pip out, drown, famish, starve, fall, succumb, yield.

croak (noun)	predecease (noun)
a harsh hoarse utterance (as of a frog)

croak (verb)	predecease (verb)
pass from physical life and lose all bodily attributes and functions necessary to sustain life	die before; die earlier than
make complaining remarks or noises under one's breath
utter a hoarse sound, like a raven