rub (v.)youdaoicibaDictYouDict[rub 词源字典]
early 14c., transitive and intransitive, 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), of uncertain origin. Related: Rubbed; rubbing.

To rub (someone) the wrong way is from 1853; probably the notion is of cats' fur. To rub noses in greeting as a sign of friendship (attested from 1822) formerly was common among Eskimos, Maoris, and some other Pacific Islanders. Rub out "obliterate" is from 1560s; underworld slang sense of "kill" is recorded from 1848, American English. Rub off "remove by rubbing" is from 1590s; meaning "have an influence" is recorded from 1959.[rub etymology, rub origin, 英语词源]
scrub (v.)youdaoicibaDictYouDict
"rub hard," early 15c., earlier shrubben (c. 1300), perhaps from Middle Dutch or Middle Low German schrubben "to scrub," or from an unrecorded Old English cognate, or from a Scandinavian source (such as Danish skrubbe "to scrub"), probably ultimately from the Proto-Germanic root of shrub, used as a cleaning tool (compare the evolution of broom, brush (n.1)).

Meaning "to cancel" is attested from 1828 (popularized during World War II with reference to flights), probably from notion of "to rub out, erase" an entry on a listing. Related: Scrubbed; scrubbing.
slime (n.)youdaoicibaDictYouDict
Old English slim "slime," from Proto-Germanic *slimaz (cognates: Old Norse slim, Old Frisian slym, Dutch slijm "slime, phlegm," German Schleim "slime"), probably related to Old English lim "birdlime; sticky substance," from PIE root *(s)lei- "slimy, sticky, slippery" (cognates: Sanskrit linati "sticks, stays, adheres to; slips into, disappears;" Russian slimak "snail;" Old Church Slavonic slina "spittle;" Old Irish sligim "to smear," leinam "I follow," literally "I stick to;" Welsh llyfn "smooth;" Greek leimax "snail," limne "marsh, pool, lake," alinein "to anoint, besmear;" Latin limus "slime, mud, mire," linere "to daub, besmear, rub out, erase"). As an insult to a person from mid-15c. Slime-mold is from 1880.