c. 1793, "to corrupt the morals of," from French démoraliser, from de- "remove" (see de-) + moral (adj.) (see moral). Said to be a coinage of the French Revolution. Sense of "lower the morale of" (especially of armies) is first recorded 1848. Related: Demoralized; demoralizing.[demoralize etymology, demoralize origin, 英语词源]