abrade v.

word-forming element meaning "away, from, from off, down," denoting disjunction, separation, departure; from Latin ab (prep.) "off, away from" in reference to space or distance, also of time, from PIE root *apo- "off, away" (also the source of Greek apo "off, away from, from," Sanskrit apa "away from," Gothic af, English of, off; see apo-).

The Latin word also denoted "agency by; source, origin; relation to, in consequence of." Since classical times usually reduced to a- before -m-, -p-, or -v-; typically abs- before -c-, -q-, or -t-.

1540s, "completely destroy," an alteration of racen "pull or knock down" (a building or town), from earlier rasen (14c.), etymologically "to scratch, slash, scrape, erase," from Old French raser "to scrape, shave," from Medieval Latin rasare, frequentative of Latin radere (past participle rasus) "to scrape, shave." This has cognates in Welsh rhathu, Breton rahein "to scrape, shave." Watkins says it is "possibly" from an extended form of the PIE root *red- "to scrape, scratch, gnaw." But de Vaan writes, "Since this word family is only found in Italo-Celtic, a PIE origin is uncertain." From 1560s as "shave off, remove by scraping," also "cut or wound slightly, graze." Related: Razed; razing.

*rēd-, Proto-Indo-European root meaning "to scrape, scratch, gnaw."

It forms (possibly) all or part of: abrade; abrasion; corrode; corrosion; erase; erode; erosion; radula; rascal; rase; rash (n.) "eruption of small red spots on skin;" raster; rat; raze; razor; rodent; rostrum; tabula rasa.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit radati "scrapes, gnaws," radanah "tooth;" Latin rodere "to gnaw, eat away," radere "to scrape;" Welsh rhathu "scrape, polish."