Taciturn, a.
Etymology: [L. taciturnus: cf. F. taciturne. See Tacit.]
Habitually silent; not given to converse; not apt to talk or speak. -- Tac"i*turn*ly, adv.
Syn. -- Silent; reserved. Taciturn, Silent. Silent has reference to the act; taciturn, to the habit. A man may be silent from circumstances; he is taciturn from disposition. The loquacious man is at times silent; one who is taciturn may now and then make an effort at conversation.
Shades of meaning
Dumb, mute, silent and speechless refer to fact or state; taciturn refers to habit and disposition. The talkative person may be stricken dumb with surprise or terror; the obstinate may remain mute; one may be silent through preoccupation of mind or of set purpose; but the taciturn person is averse to the utterance of thought or feeling and to communication with others, either from natural disposition or for the occasion. One who is silent does not speak at all; one who is taciturn speaks when compelled, but in a grudging way that repels further approach. Reserved suggests more of method and intention than taciturn, applying often to some special time or topic; one who is communicative regarding all else may be reserved about his business. Reserved is thus closely equivalent to uncommunicative, but is a somewhat stronger word, often suggesting pride or haughtiness, as when we say one is reserved toward inferiors. Compare pride.