From The Collaborative International Dictionary of English v.0.48 [gcide]:
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]
From WordNet (r) 3.0 (2006) [wn]:
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]