Source : Webster's Revised Unabridged Dictionary (1913)

Testiness \Tes"ti*ness\, n.
   The quality or state of being testy; fretfulness; petulance.

         Testiness is a disposition or aptness to be angry.
                                                  --Locke.

Source : WordNet®

testiness
     n : feeling easily irritated [syn: {touchiness}, {tetchiness}]