Standard nationality term — country name 埃塞俄比亚 (Ethiopia, from CC-CEDICT) + 人 (person). Following the Chinese pattern <country>+人, e.g. 美国人, 日本人, 巴西人. Note Hong Kong and Taiwan use the variant 衣索比亚 (Yīsuǒbǐyà), so an Ethiopian is 衣索比亚人 there.
culture
Per Xinhua, the term covers peoples of the Horn of Africa region (Ethiopia, Somalia, Djibouti) — historically a regional designation. In modern news writing it's almost always strict national citizenship.
