omnilingual

1. not comparableHaving the ability to speak, or to understand, all languages.

   The Sandpipers are omnilingual and sing in 11 different languages.

   1969, Congressional Record, United States Congress, page 8252

   2 more examples

   Sir, my omnilingual Diorama having recently appeared in your useful publication, unconnected with some of the proofs that it has a just claim to such a comprehensive title, I shall now, with your permission, submit a prospectus of my universal characters contrasted with those which are most current over the Asiatic Peninsula, to the inspection of many Orientalists among your readers, very well qualified to decide impartially on the comparative merits of my scheme, at least in its application to the two indispensable languages for British India: namely, the Hindoostanee and Persian tongue.

   1825, The Oriental Herald 1825-08: Volume 6, Issue 20, Open Court Publishing Company, page 302

   Because they are in some sense part of an omnilingual scholarly vocabulary, many instructors require their students to learn them and use them.

   1960, The Voice Out of the Whirlwind: The Book of Job, Chandler Pub. Company, page 328

plural omnilinguals

1. A person who has the ability to speak, or to understand, all languages

   Synonyms: omnilinguist