(British demeanour)

BEARING, DEPORTMENT, DEMEANOR, MIEN, MANNER, CARRIAGE mean the outward manifestation of personality or attitude.

BEARING is the most general of these words but now usually implies characteristic posture.

e.g. a woman of regal bearing

DEPORTMENT suggests actions or behavior as formed by breeding or training.

e.g. your deportment was atrocious

DEMEANOR suggests one's attitude toward others as expressed in outward behavior.

e.g. the haughty demeanor of the headwaiter

MIEN is a literary term referring both to bearing and demeanor.

e.g. a mien of supreme self-satisfaction

MANNER implies characteristic or customary way of moving and gesturing and addressing others.

e.g. the imperious manner of a man used to giving orders

CARRIAGE applies chiefly to habitual posture in standing or walking.

e.g. the kind of carriage learned at boarding school

source: [この素晴らしい世界に祝福を!のアクアが高飛車な態度なGIF画像｜無料GIF画像検索 GIFMAGAZINE 864454]

outward behavior or bearing:

｟かたく｠ ; 〖時にa ～〗 態度(manner); ふるまい(behavior)

e.g. a quiet, somber demeanor.

late 15th century: from demean2, probably influenced by obsolete havour‘behavior’.