weep vs sob

weep is not a noun while sob is a noun.

Word	Noun	Adjective	Verb	Adverb
weep	No	No	Yes	No
sob	Yes	No	Yes	No

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

Other hyponyms of weep include mewl, pule, wail, whimper, bawl, tear, blub, blubber, sniffle, snivel, snuffle.

weep (noun)	sob (noun)
	convulsive gasp made while weeping

weep (verb)	sob (verb)
shed tears because of sadness, rage, or pain	weep convulsively