/ ˈtæsɪtɜːn; NAmE -tɜːrn/ adjective
tending not to say very much, in a way that seems unfriendly
► taci·turn·ity / ˌtæsɪˈtɜːnəti; NAmE -ˈtɜːrn-/ noun [ U ]
••
WORD ORIGIN
late 18th cent.: from Latin taciturnus , from tacitus , past participle of tacere be silent.