I. -ˈli-t(ə-)rəl adjective
Etymology: tri- + Latin littera letter
Date: 1751
: consisting of three letters and especially of three consonants
triliteral roots in Semitic languages
• tri·lit·er·al·ism -t(ə-)rə-ˌli-zəm noun
II. noun
Date: circa 1828
: a root or word that is triliteral