The Collaborative International Dictionary of English v.0.48:

Roil \Roil\, v. i.
   1. To wander; to roam. [Obs.]
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   2. To romp. [Prov. Eng.] --Halliwell.
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The Collaborative International Dictionary of English v.0.48:

Roil \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.
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   2. To disturb, as the temper; to ruffle the temper of; to
      rouse the passion of resentment in; to perplex.
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            That his friends should believe it, was what roiled
            him [Judge Jeffreys] exceedingly.     --R. North.
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   Note: Provincial in England and colloquial in the United
         States. A commoner, but less approved, form is rile.
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WordNet (r) 3.0 (2006):

roil
    v 1: be agitated; "the sea was churning in the storm" [syn:
         churn, boil, moil, roil]
    2: make turbid by stirring up the sediments of [syn: roil,
       rile]