even-tempered
UK: ˌiːvən ˈtempəd | US: ˌiːvən ˈtempərd
adj. calm and not easily annoyed or upset
adj. having a balanced or steady disposition
The word combines "even," from Old English efen (meaning "level" or "balanced"), with "temper," from Latin temperare (to mix or regulate). The suffix "-ed" turns it into an adjective. Historically, "temper" referred to the balance of bodily humors in medieval medicine, and "even-tempered" evolved to describe someone whose emotional state is consistently calm and balanced.
She remained even-tempered despite the chaotic situation.
His even-tempered nature makes him an excellent mediator.
The teacher's even-tempered response diffused the argument.
Being even-tempered is essential for high-pressure jobs.
Dogs with even-tempered dispositions are easier to train.