Eonism

Eonism was a term invented by Havelock Ellis to refer to transgender conditions. He named it after Charles-Geneviève-Louis-Auguste-André-Timothée d'Éon de Beaumont (the Chevalier d'Éon, 1728–1810) a French spy and diplomat, born a man, who lived as a woman for the last 33 years of her life, and whose name is also commemorated in the Beaumont Society.

The term is no longer in general use.