The Collaborative International Dictionary of English v.0.48:

Choler \Chol"er\, n. [OE. coler, F. col[`e]re anger, L. cholera
   a bilious complaint, fr. Gr. ? cholera, fr. ?, cholh`, bile.
   See Gall, and cf. Cholera.]
   1. The bile; -- formerly supposed to be the seat and cause of
      irascibility. [Obs.]
      [1913 Webster]

            His [Richard Hooker's] complexion . . . was
            sanguine, with a mixture of choler; and yet his
            motion was slow.                      --I. Warton.
      [1913 Webster]

   2. Irritation of the passions; anger; wrath.
      [1913 Webster]

            He is rash and very sudden in choler. --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

choler
    n 1: an irritable petulant feeling [syn: irritability,
         crossness, fretfulness, fussiness, peevishness,
         petulance, choler]
    2: a strong emotion; a feeling that is oriented toward some real
       or supposed grievance [syn: anger, choler, ire]
    3: a humor that was once believed to be secreted by the liver
       and to cause irritability and anger [syn: yellow bile,
       choler]