Habitually untalkative. See Synonyms at silent.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "taciturn" in a sentence
"His bosses are telling him to take it easy; he's charging about in taciturn Heathcliffian style following his hunches and shouting at a woman with "locked-in" syndrome."
"Gen. Kosaner, appointed chief of the general staff last August, was known as a taciturn hardliner within the military."
"One of the advantages of being taciturn is that it is rare for your words to get you into trouble."