Transferred use of the surname, which has a double origin. In part it is a local name for someone who lived in a valley (Middle English dene, Old English denu) and in part an occupational name for someone who served as a dean, i.e. ecclesiastical supervisor (Latin decanus). The given name also sometimes represents Italian Dino (a short form of names such as Bernardino), as in the case of the American actor and singer Dean Martin (1917–95).
French: habitational name from any of various places in France named Beauregard for their fine view or fine aspect, for example in Ain, Dordogne, Drôme, Lot, and Puy-de-Dôme, from beau ‘fair’, ‘lovely’ + regard ‘aspect’, ‘outlook’.