"having lost one's place in the social order," 1887, from French déclassé, past participle of déclasser "to cause to lose class," from de-, privative prefix (see de-) + classer "to class," from classe (n.), from Latin classis (see class (n.)). In italics in English until c. 1920; nativized form declassed is attested from 1873.
Fallen or put out of one's proper class or place or any definite and recognized position or rank in the social system: applied to persons who by misfortune or their own fault have lost social or business standing, and are not counted as part of any recognize class of society. [Century Dictionary, 1897]