verb (used with object)
- to render (water, wine, etc.) turbid by stirring up sediment.
- to disturb or disquiet; irritate; vex: to be roiled by a delay.
verb (used without object)
- to move or proceed turbulently.
- (tr) to make (a liquid) cloudy or turbid by stirring up dregs or sediment
- (intr) (esp of a liquid) to be agitated or disturbed
- (intr) dialect to be noisy or boisterous
- (tr) another word (now rare) for rile (def. 1)
1580s, of uncertain origin, probably from Middle French rouiller “to rust, make muddy,” from Old French roil “mud, muck, rust” (12c.), from Vulgar Latin *robicula, from Latin robigo “rust” (see robust). An earlier borrowing of the French verb is Middle English roil “to roam or rove about” (early 14c.). Related: Roiled; roiling.