Of a person: not readily roused or moved to anger or some other emotion or tendency. Also with in or infinitive.

Not capable of being, or not liable to be, mentally perturbed or agitated; unexcitable; calm, composed.

Of a sober mind; temperate; self-controlled; rational; sensible. Also absol.

Very or appropriately settled, sober, or staid.

Of the mind, character, etc.: Rendered staid, steadfast, or sober.

Of a temperate or moderate disposition; not readily excited or carried away; of a calm, dispassionate judgement.

Of a person or his mind: Not easily perturbed or discomposed; balanced. Of the head: Free from giddiness. Of the eye: Not diverted from its object…

Incapable of being provoked; not provokable.

Having a pleasant and equable disposition; not easily angered or annoyed. Also: characterized by or characteristic of such a disposition.

Not irritable or susceptible of excitement; devoid of irritability.

Mentally and emotionally stable; (now) spec. fully adapted psychologically and behaviourally to one's (social) environment; cf. adjusted, adj. 2b.

(un-, prefix1 affix 1.)

Not excitable; not liable to excitement.

Incapable of being unduly excited, agitated, or disturbed; calm, collected, imperturbable.

Befitting a churchwarden; reminiscent or characteristic of a churchwarden; spec. staid, respectable.

= unrufflable, adj.

(un-, prefix1 affix 1b.)

Incapable of being roused. Also: (of sleep) from which one cannot be roused.

Originally: †having or characterized by a well-balanced mental temperament; measured, restrained (obsolete). In later use: having a pleasant…

Characteristic of middle-aged people. Cf. middle age, n. 2.

(un-, prefix1 affix 1.)

Not subject to nervous excitement or anxiety; imperturbable.