Pattern: country name + 人 = nationality. 意大利 (Italy) + 人 (person) -> 意大利人 (Italian). Same pattern: 中国人 Chinese, 法国人 French, 日本人 Japanese. The country name 意大利 is itself a phonetic transliteration of 'Italia'.
culture
意大利 was adopted via Matteo Ricci (利玛窦) and other Jesuits in the late Ming dynasty - the characters were chosen partly for sound ('Yi-da-li' ≈ 'I-ta-lia'), partly for auspicious meaning ('thought-great-benefit').
