step on it vs tear

step on it is not a noun while tear is a noun.

Word	Noun	Adjective	Verb	Adverb
step on it	No	No	Yes	No
tear	Yes	No	Yes	No

As verbs, tear is a hyponym of step on it; that is, tear is a word with a more specific, narrower meaning than step on it:

Other hyponyms of step on it include barge, push forward, thrust ahead, buck, charge, shoot, shoot down, dart, dash, flash, scoot, scud, shoot.

step on it (noun)	tear (noun)
	a drop of the clear salty saline solution secreted by the lacrimal glands
	the act of tearing
	an occasion for excessive eating or drinking
	an opening made forcibly as by pulling apart

step on it (verb)	tear (verb)
move hurridly	separate or cause to separate abruptly
	to separate or be separated by force
	strip of feathers
	move quickly and violently
	fill with tears or shed tears