transsexualism (n.) Look up transsexualism at Dictionary.com
"intense desire to change one's sexual status, including the anatomical structure," 1953, coined by U.S. physician Harry Benjamin (1885-1986) from trans- + sexual. Transsexuality is recorded from 1941, but was used at first to mean "homosexuality" or "bisexuality." In the current sense from 1955.