imperturbable adj : not easily perturbed or excited or upset; marked by extreme calm and composure; "hitherto imperturbable, he now showed signs of alarm"; "an imperturbable self-possession"; "unflappable in a crisis" [syn: unflappable]

English

Adjective

imperturbable

1. not easily perturbed, upset or excited
2. calm and collected, even under pressure

balanced, bovine, collected, complacent, composed, cool, dispassionate, dull, even-tempered, fast, fiducial, firm, firm as Gibraltar, impassive, in equilibrium, inexcitable, inirritable, nonchalant, patient, predictable, reliable, secure, self-satisfied, smug, solid, sound, stable, steadfast, steady, stoic, stolid, substantial, unaffected, undisturbable, unflappable, unflinching, unirritable, unmoved, unnervous, unpassionate, unshakable, untouched, unwavering, well-balanced, without nerves