http://dictionary.reference.com/search?q=irascible
Irascible, adj.
1. Prone to outbursts of temper; easily angered.
2. Characterized by or resulting from anger.
Middle English, from Old French, from Late Latin irascibilis, from Latin irasci, to be angry, from ira, anger.
I haven’t done a Word of the Moment recently – I feel a lot happier now. Etymology makes everything better. 🙂