noun
full-width Roman character
Refers to Roman letters and digits that occupy the same width as a CJK character, as opposed to half-width (半角) characters. Common in Japanese computing and typography.
パスワードには全角ローマ字を使わないでください。
Please do not use full-width Roman characters in your password.
Compound of 全角 (full-width) and ローマ字 (Roman characters). The term is technical and modern, arising from Japanese character encoding standards.