Roil (?), v. t. [imp. & p. p.Roiled; p. pr. & vb. n.Roiling.] [Cf. OE. roilen to wander; possibly fr. OF. roeler to roll, equiv. to F. rouler. See Roll, v., and cf. Rile.] 1. To render turbid by stirring up the dregs or sediment of; as, to roil wine, cider, etc., in casks or bottles; to roil a spring.
2. To disturb, as the temper; to ruffle the temper of; to rouse the passion of resentment in; to perplex.
That his friends should believe it, was what roiled him exceedingly. R. North.
☞ Provincial in England and colloquial in the United States. A commoner, but less approved, form is rile.