mid-14c., rascaile "people of the lowest class, the general mass; rabble or foot-soldiers of an army" (senses now obsolete), also singular, "low, tricky, dishonest person," from Old French rascaille "rabble, mob" (12c., Modern French racaille), as Cotgrave's French-English Dictionary (1611) defines it: "the rascality or base and rascall sort, the scumme, dregs, offals, outcasts, of any company."

This is of uncertain origin, perhaps a diminutive from Old French rascler, from Vulgar Latin *rasicare "to scrape" (see rash (n.)) on the notion of "the scrapings." "[U]sed in objurgation with much latitude, and often, like rogue, with slight meaning" [Century Dictionary]. Used also in Middle English of animals unfit to chase as game on account of some quality, especially a lean deer. Also formerly an adjective.

"low, mean, unprincipled, characteristic of a rascal," 1590s, from rascal + -ly (1). The earlier adjective was simply rascal (early 15c.).

1570s, "low and vulgar people collectively;" 1590s, "character or actions of a rascal;" see rascal + -ity. Middle English had rascaldry "common soldiers" (mid-15c.); Carlyle (1837) used rascaldom "the sphere or domain of rascals."

"A rascally, disorderly, or despicable person" [Century Dictionary], 1690s, alteration of rascallion (1640s), a fanciful elaboration of rascal (q.v.). It had a parallel in now-extinct rampallion (1590s), from Middle English ramp (n.2) "ill-behaved woman." Also compare rascabilian (1620s). Rapscallionry "rascals collectively" is marked "[Rare.]" in Century Dictionary (1897); Galsworthy used rapscallionism.

*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."

mid-15c., "servant, attendant of a knight," from Old French varlet (14c.), variant of vaslet, originally "squire, young man," from Old French vassal (see vassal). The meaning "rascal, rogue" is 1540s.

16c., from French furtif (16c.), from Latin furtivus "stolen," hence also "hidden, secret," from furtum "theft, robbery; a stolen thing," from fur (genitive furis) "a thief, extortioner," also a general term of abuse, "rascal, rogue," probably from PIE *bhor-, from root *bher- (1) "to carry; to bear children." Related: Furtiveness.