sesquilingual adjective2 •(rare) Pertaining to one language, plus a second in a limited capacity, degree, or content.Typically, it is believed that this sesquilingual discourse is due to the absence of suitable terms in the inferior language. — 1976 •(rare) Able to communicate fluently in one language, but only to a degree in another.Being already sesquilingual, the Hong Kong Chinese are therefore quite receptive to the teaching of another language. — 1978
