early 14c., rubben, transitive and intransitive, "apply friction on a surface; massage (the body or a part of it)," a word of uncertain origin, perhaps related to East Frisian rubben "to scratch, rub," and Low German rubbeling "rough, uneven," or similar words in Scandinavian (compare Danish rubbe "to rub, scrub," Norwegian rubba), all of uncertain origin. Related: Rubbed; rubbing.
To rub (someone) the wrong way is by 1853; probably the notion is of animals and their fur. To rub noses in greeting as a sign of friendship (attested from 1822) said to have been formerly common among Eskimos, Maoris, and some other Pacific Islanders. Rub out is from late 14c. as "scrape away," also figurative; the meaning "obliterate" is from 1560s; underworld slang sense of "kill" is recorded from 1848, American English. Rub off "remove by rubbing" is from 1590s; rub off on "have an influence on" is recorded by 1959.
"act of rubbing," 1610s, from rub (v.). Earlier it meant "obstacle, inequality on ground" (1580s), a sense common in 17c., especially in the game of bowls, in reference to something that slows or deflects a bowl, on the notion of "rubbing against" it. Hence the figure in Hamlet's there's the rub (1602). The earlier noun was rubbing (late 14c.).