bête noire noun alsobête noir\ˌbetnəˈwär, betˈnw-, -āt-, -wȧ(r\ (pluralbêtes noiresalsobêtes noirs \-är(z), -ȧz, -ȧ(r\) Etymology: French bête noire, literally, black beast : a person or thing usually strongly and persistently detested, feared, or avoided < an idiosyncratic driver whose bête noir was the left turn — Marylin Bender >