dis-,not,逆を作る。本来は同じ服装ではなく、服装や外見を変えることを指し、侮蔑的な意味の言葉にちなむ。
It is most absurdly said, in popular language, of any man, that he is disguised in liquor; for, on the contrary, most men are disguised by sobriety. [Thomas de Quincy, "Confessions of an English Opium-Eater," 1856]Related: Disguised; disguising.