The story
- Proto-Indo-European*terh₂-
- Proto-Indo-European*térh₂t
- Proto-Indo-European*tr̥h₂ónts
- Proto-Indo-European*tr̥h₂n̥ts
- Proto-Italic*trāns
- Proto-Italic*trāns-
- Latintrans-
- Englishtrans-
- Proto-Indo-European*sek-
- Proto-Indo-European*séks-u-s
- Proto-Italic*seksus
- Proto-Indo-European*sek-
- Proto-Indo-European*sékh₁yeti
- Proto-Italic*sekaō
- Latinsecō
- Latinsecāre?
- Latinsexus
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- Latinsexuālis
- Englishsexual
- English todaytranssexual
From trans- + sexual. Introduced to English along with transsexualism by David Oliver Cauldwell in 1949, based on the German word Transsexualismus coined by Magnus Hirschfeld in 1923. Popularized in the mid 1960s, around the same time that transgender was coined; transgender had become an umbrella term and largely but not entirely displaced transsexual by the 1990s.
Etymology from Wiktionary, CC BY-SA 4.0.