(a.) Cautious in speaking; secret; wary; uncommunicative.

brief brusque close close-lipped close-tongued concise curt dark discreet dumb economical of words evasive indisposed to talk laconic mum mute quiet reserved reticent secret secretive shifty short silent snug sparing of words speechless taciturn terse tight-lipped tongue-tied uncommunicative unloquacious untalkative word-bound wordless