physical contact vs rub

physical contact and rub both are nouns.

Word	Noun	Adjective	Verb	Adverb
physical contact	Yes	No	No	No
rub	Yes	No	Yes	No

As nouns, rub is a hyponym of physical contact; that is, rub is a word with a more specific, narrower meaning than physical contact:

Other hyponyms of physical contact include wipe, fair ball, snick, laying on.

physical contact (noun)	rub (noun)
the act of touching physically	the act of rubbing or wiping
	an unforeseen obstacle

physical contact (verb)	rub (verb)
	move over something with pressure
	cause friction
	scrape or rub as if to relieve itching