Sex

Sex was a process through which two or more individuals proceed through a process of sexual gratification.

The term 'sexually pair bonded' was used to describe a two beings in a sexual relationship in the 24th century. (NA: Shakedown)

Sex was also used to describe the gender of a particular species.

Other contexts

 * Many Time Lords dream of being a different sex (gender). (NA: Human Nature)
 * In one possible timeline, Time Lords who commit suicide regenerate into a body of the opposite sex. (DWU: Exile)
 * Iris Wildthyme confided in Sam and the Doctor that regeneration is treated on Gallifrey the same way that sex is treated on Earth. (EDA: The Scarlet Empress)
 * Jason Kane wrote several xenopornography novels including Nights of the Perfumed Tentacle based on his sexual encounters with various species. (BNA: Beige Planet Mars)