bilingualism (n.)

1818, "speaking two languages;" 1825, "expressed in two languages;" see bi- "two" + lingual. Latin bilinguis meant literally "two-tongued," and, figuratively, "speaking a jumble of languages," also "double-tongued, hypocritical, false."

word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.