The Collaborative International Dictionary of English v.0.48:
Irascibility \I*ras`ci*bil"i*ty\, n. [Cf. F. irascibilit['e].] The quality or state of being irascible; irritability of temper; irascibleness. [1913 Webster]WordNet (r) 3.0 (2006):
irascibility n 1: a feeling of resentful anger [syn: irascibility, short temper, spleen, quick temper]