Wikipedia
Huan-a is a Hokkien word which means foreigner. 番 means 'foreign', and 仔 is a Hokkien noun suffix. This phrase is commonly perceived as derogatory by most non-Chinese speakers. Chinese Indonesians, Chinese Singaporeans, Chinese Filipinos and Chinese Malaysians use this word to refer to non-Chinese Southeast Asians. During the Japanese occupation of Taiwan, the Japanese were called huan-a by Native Taiwanese, with geisha called hoan-á-ke (番仔雞, lit. "foreign chicken") and the wives of Japanese men called hoan-á-chiú-kan (番仔酒矸, lit. "foreign liquor bottle"). Huan-a is now commonly used in Taiwan to refer to indigenous peoples (the Taiwanese aborigines). In Penang, huan-a are used to refer to Malays, whereas ang moh refers to Europeans and Kling na refer to Tamils.
Back days, the term is used by Han Chinese to refer Mongolians invaders. Basically Huanna connotes "barbaric foreigner".
Similarly, the word fan-kui ( is a Mandarin Chinese word which means dark foreigner. 瞶 means 'dim' or 'dark'. This phrase is used by Chinese Indonesians to imply Indonesians due to their dark skin color. Indonesians consider this phrase to be rude and racist.