trilingual

[ trahy-ling-gwuh l or, Canadian, -ling-gyoo-uh l ]

/ traɪˈlɪŋ gwəl or, Canadian, -ˈlɪŋ gyu əl /

using, speaking, or involving three languages.

Origin of trilingual

1825–35; < Latin trilingu(is) triple-tongued + -al¹. See tri-, lingual

tri·lin·gual·ism, noun tri·lin·gual·ly, adverb

Trilingual, trī-ling′gwal, adj. consisting of three tongues or languages.

Chambers's Twentieth Century Dictionary (part 4 of 4: S-Z and supplements) |Various
It is probable that there was actual diversity in the trilingual versions.

Jesus the Christ |James Edward Talmage
It is trilingual--viz., Chinese, Uighur, and runic or Yenissei characters.

The American Journal of Archaeology, 1893-1 |Various
The first clue to these questions was, as in the parallel case of Egypt, afforded by a trilingual inscription.

Human Origins |Samuel Laing

The only inscription at Wan that I could not copy was the trilingual tablet of Xerxes.

Discoveries among the Ruins of Nineveh and Babylon |Austen H. Layard

trilingual

/ (traɪˈlɪŋɡwəl) /

able to speak three languages fluently

expressed or written in three languages

trilingualism, noun trilingually, adverb