Nausea literally means ship-sickness. The word comes from Latin nausea, borrowed directly from Greek nausia, which derived from naus, a ship. In its original sense, nausea referred exclusively to the misery of being seasick on a vessel — that specific combination of dizziness, cold sweat, and stomach revolt that afflicts passengers on rough water.
The Greek root naus belongs to one of the oldest word families in Indo-European languages. It produced Latin navis (ship), from which English gets navy, navigate, and nave (the central part of a church, shaped like an inverted hull). It also generated nautical, nautilus, and the -naut suffix in astronaut and cosmonaut. All these words connect to the same prehistoric term for a boat.
Latin nausea expanded beyond maritime contexts even in Roman times. Cicero used it figuratively to mean disgust or loathing. English borrowed the word in the 15th century and continued this broadening. By the 17th century, nausea covered any stomach discomfort, whether caused by illness, food, pregnancy, or emotional distress, with no ship required.
The word took an unexpected detour through French. Old French adapted Latin nausea into noise, which originally meant an uproar or disturbance — the semantic path running from seasickness to the groaning and retching of sick passengers to loud unpleasant sound to sound in general. English borrowed this French form as noise, meaning the English words nausea and noise are doublets: two words from the same Latin source that entered English by different routes and ended up with completely different meanings.
Jean-Paul Sartre titled his 1938 existentialist novel La Nausee (Nausea), using the physical sensation as a metaphor for existential dread — the philosophical seasickness of confronting a meaningless universe.