give-up the ghost vs croak

give-up the ghost is not a noun while croak is a noun.

Word	Noun	Adjective	Verb	Adverb
give-up the ghost	No	No	Yes	No
croak	Yes	No	Yes	No

As verbs, give-up the ghost and croak are synonyms defined as:

give-up the ghost and croak: pass from physical life and lose all bodily attributes and functions necessary to sustain life

give-up the ghost (noun)	croak (noun)
	a harsh hoarse utterance (as of a frog)

give-up the ghost (verb)	croak (verb)
pass from physical life and lose all bodily attributes and functions necessary to sustain life	pass from physical life and lose all bodily attributes and functions necessary to sustain life
	make complaining remarks or noises under one's breath
	utter a hoarse sound, like a raven