buy the farm vs change state

buy the farm and change state both are verbs.

Word	Noun	Adjective	Verb	Adverb
buy the farm	No	No	Yes	No
change state	No	No	Yes	No

As verbs, change state is a hypernym of buy the farm; that is, change state is a word with a broader meaning than buy the farm:

buy the farm: pass from physical life and lose all bodily attributes and functions necessary to sustain life
change state: undergo a transformation or a change of position or action

Other hypernyms of buy the farm include turn.

buy the farm (verb)	change state (verb)
pass from physical life and lose all bodily attributes and functions necessary to sustain life	undergo a transformation or a change of position or action