The story
- Proto-Indo-European*sem-
- Proto-Indo-European*sḿ̥teros
- Proto-Hellenic*hə́teros
- Ancient Greekἕτερος (héteros)
- Englishhetero-
- 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 todayheterosexual
From hetero- + -sexual. Earliest citation from 1892, in C.G. Craddock's translation of Krafft-Ebbing's Psychopathia Sexualis.
Etymology from Wiktionary, CC BY-SA 4.0.