The Collaborative International Dictionary of English v.0.48:

Rile \Rile\ (r[imac]l), v. t. [imp. & p. p. Riled (r[imac]ld);
   p. pr. & vb. n. Riling.] [See Roil.]
   1. To render turbid or muddy; to stir up; to roil.
      [1913 Webster]

   2. To stir up in feelings; to make angry; to vex.
      [1913 Webster]

   Note: In both senses provincial in England and colloquial in
         the United States.
         [1913 Webster]

WordNet (r) 3.0 (2006):

rile
    v 1: cause annoyance in; disturb, especially by minor
         irritations; "Mosquitoes buzzing in my ear really bothers
         me"; "It irritates me that she never closes the door after
         she leaves" [syn: annoy, rag, get to, bother, get
         at, irritate, rile, nark, nettle, gravel, vex,
         chafe, devil]
    2: make turbid by stirring up the sediments of [syn: roil,
       rile]

Moby Thesaurus II by Grady Ward, 1.0:

98 Moby Thesaurus words for "rile":
   aggravate, agitate, annoy, arouse, badger, bait, be at, beat,
   beat up, bedevil, beset, bother, bristle, brown off, bug, bullyrag,
   burn up, chafe, chivy, churn, churn up, convulse, devil,
   disarrange, discompose, disquiet, distemper, disturb, dog,
   embitter, exasperate, excite, exercise, fash, ferment, flurry,
   fret, get, grate, gripe, harass, harry, heckle, hector, hound,
   huff, incense, inflame, irk, irritate, miff, molest, mud, muddle,
   muddy, nag, needle, nettle, nudzh, paddle, peeve, persecute,
   perturb, perturbate, pester, pick on, pique, plague,
   pluck the beard, pother, provoke, put out, rankle, ride, ripple,
   roil, roughen, ruffle, rumple, set up, shake, shake up, stir,
   stir the blood, stir up, swirl, tease, torment, trouble,
   try the patience, tweak the nose, upset, vex, whip, whip up, whisk,
   work up, worry