Lewis & Short

irrītābĭlis (inr-), e, adj. [1. irrito].

  1. I. Easily excited or enraged, irritable: irritabiles esse animos optimorum saepe hominum, Cic. Att. 1, 17, 4: genus vatum, Hor. Ep. 2, 2, 102; Amm. 18, 6, 18.
  2. * II. Act., easily exciting: formae, Lact. 6, 23, 5.