American Heritage® Dictionary of the English Language, Fourth
Edition - adj. Irritated, impatient, or exasperated; peevish: a
testy cab driver; a testy refusal to help. Century Dictionary
and Cyclopedia - Irritable; irascible; choleric; cross;
petulant. - Synonyms Pettish, touchy, waspish, snappish,
peevish, splenetic, captious, peppery. GNU Webster's 1913 - adj.
Fretful; peevish; petulant; easily irritated. - adj. easily
irritated or annoyed - Middle English testif ("headstrong"),
from Old French testu, from teste ("head") + -u. Compare modern
French tête ("head"), têtu ("stubborn"). (Wiktionary) -
Alteration of Middle English testif, headstrong, from Old French
testu, from teste, head, from Late Latin testa, skull; see
teston. (American Heritage® Dictionary of the English Language,
Fourth Edition) “She seems to think getting testy is that same
as showing strength.” “She comes back, a little testy: "Pollo is
the Spanish word for CHICKEN!” “I especially loved the way she
said "testy" - a defining Venetian cha