early 15c., "native of Italy," from Italian Italiano, from Italia "Italy" (see Italy). Meaning "the Italian language" is late 14c. As an adjective from 1510s. Earlier the Italians were the Italies (late 14c.).
-ism
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.