1540s, of persons, "having or indicating great strength, muscular, vigorous," from French robuste (14c.) and directly from Latin robustus "strong and hardy," literally "as strong as oak," originally "oaken," from robur, robus "hard timber, strength," also "a special kind of oak," named for its reddish heartwood, from Latin ruber "red" (related to robigo "rust"), from PIE root *reudh- "red, ruddy." Related: Robustly; robustness; robusticity.
Robustious (1540s) was an elaborated form common in 17c. (see "Hamlet" iii.2), with more of a sense of "rough, violent, rude;" according to OED it fell from use by mid-18c., but was somewhat revived by mid-19c. antiquarian writers. Related: Robustiously; robustiousness.
"uproar, disturbance, riot," 1764 (Foote), a word of unknown origin, "prob. a fanciful formation" [OED], possibly an alteration of robustious "boisterous, noisy" (1540s; see robust). Rumpus room "play room for children in a family home" is from 1938.
mid-15c., corroboracioun, "act of strengthening, support" (a sense now obsolete), from Late Latin corroborationem (nominative corroboratio), noun of action from past-participle stem of Latin corroborare "to strengthen, invigorate," from assimilated form of com "with, together," here perhaps "thoroughly" (see com-) + roborare "to make strong," from robur, robus "strength," (see robust). Meaning "act of confirming, verification, confirmation" is attested by 1768.
1520s, "to give (legal) confirmation to," from Latin corroboratus, past participle of corroborare "to strengthen, invigorate," from assimilated form of com "with, together," here perhaps "thoroughly" (see com-) + roborare "to make strong," from robur, robus "strength," (see robust).
Meaning "to strengthen by evidence, to confirm" is from 1706. Sometimes 16c.-18c. in its literal Latin sense "make strong or add strength to," especially of medicines. Related: Corroborated; corroborating; corroborative.
1580s, "render (liquid) turbid or muddy by stirring up dregs or sediment," also figurative, "excite to some degree of anger, perturb," a word of uncertain origin. Perhaps it is from French rouiller "to rust, make muddy," from Old French roil "mud, muck, rust" (12c.), from Vulgar Latin *robicula, from Latin robigo "rust" (see robust). Or perhaps from Old French ruiler "to mix mortar," from late Latin regulare "to regulate" (see regulate). Or perhaps somehow imitative. An earlier borrowing of the French verb is Middle English roil "to roam or rove about" (early 14c.); also compare rile (v.), formerly the common colloquial form in the U.S. Related: Roiled; roiling.
It forms all or part of: bilirubin; corroborate; Eritrea; erysipelas; erythema; erythro-; Radnor; red; redskin; roan; robust; rooibos; Rotwelsch; rouge; roux; rowan; rubella; rubicund; rubric; ruby; ruddock; ruddy; rufous; Rufus; russet; rust.
It is the hypothetical source of/evidence for its existence is provided by: Latin ruber, also dialectal rufus "light red," mostly of hair; Greek erythros; Sanskrit rudhira-; Avestan raoidita-; Old Church Slavonic rudru, Polish rumiany, Russian rumjanyj "flushed, red," of complexions, etc.; Lithuanian raudas; Old Irish ruad, Welsh rhudd, Breton ruz "red."
"tall and sturdy, robust," originally applied to women, 1650s, from present participle of strap (v.), apparently in the sense of "to beat with a strap." Compare similar senses of whopping, spanking, bouncing and other present-participle adjectives of violent action expressing something large in size.