buy the farm vs buy it

buy the farm and buy it both are verbs.

Word	Noun	Adjective	Verb	Adverb
buy the farm	No	No	Yes	No
buy it	No	No	Yes	No

As verbs, buy it is a hyponym of buy the farm; that is, buy it is a word with a more specific, narrower meaning than buy the farm:

buy the farm: pass from physical life and lose all bodily attributes and functions necessary to sustain life
buy it: be killed or die

Other hyponyms of buy the farm include abort, asphyxiate, stifle, suffocate, pip out, drown, predecease, famish, starve, fall, succumb, yield.

buy the farm (verb)	buy it (verb)
pass from physical life and lose all bodily attributes and functions necessary to sustain life	be killed or die