In Ursula K. Le Guin’s “The Left Hand of Darkness,” the Gethenian term for the sexual phase is kemmer.
Gethenians are ambisexual rather than permanently male or female. For most of each roughly 26-day lunar cycle, they remain sexually latent in an androgynous state. During kemmer, they develop male or female sexual characteristics, with neither role permanently assigned; biological and social context can influence which role an individual takes.
The contrast between kemmer and ordinary human sexuality is central to Genly Ai’s difficulties on Gethen. His assumptions about fixed gender make it harder for him to understand Gethenian customs, politics, and his relationship with Estraven. The novel’s two major societies, Karhide and Orgoreyn, also interpret intimacy and social status through cultures unfamiliar to Ai.
Kemmer is often confused with Karhide, a kingdom; Handdara, a religion; or shifgrethor, a system of prestige and indirect social maneuvering. Le Guin published the novel in 1969, and it won both the Hugo and Nebula Awards for Best Novel in 1970.