Testiest

Part of speech: adjective

Definitions

1. Marked by a tendency to become irritated or provoked in response to stimuli
2. Exhibiting a disposition that becomes easily annoyed or displeased under various circumstances
3. Showing a quickness to anger or irritation when faced with minor annoyances

Etymology: "Testiest" is simply the superlative of "testy," so the real story belongs to its base word. In Middle English, "testy" appeared as "testif," meaning "headstrong," and it came from Old French "testu," built from "teste" ("head") with the suffix "-u." Its nearest modern relative is French "têtu," which still means "stubborn," so the link between a head and a hard-headed temperament has survived in French. The sense of irritability came later. The word's original core was obstinacy, the stubborn refusal to yield that a headstrong person shows, and the idea of being quick to take offence gradually grew out of that picture of someone who will not give way. The shift from "stubborn" to "easily provoked" is the change that gives the modern meaning its edge.

Synonyms: irritable, grumpy, touchy, sensitive, cross

Antonyms: calm, content, easygoing, untroubled, peaceful