From Latin *dormire* ("to sleep"), itself from Proto-Indo-European *drem-* ("to sleep, to be inactive"). Cognates include Spanish *dormir*, Italian *dormire*, and Portuguese *dormir*. The English word "dormitory" shares the same root.

In French culture, sleep and rest are taken seriously — the expression *dormir comme un loir* ("to sleep like a dormouse") is a common way to describe someone who sleeps very soundly. The verb also appears in the fairy-tale title *La Belle au bois dormant* (Sleeping Beauty), literally "the beauty sleeping in the woods." Note that English "dormant" is a direct false friend in disguise: it looks borrowed but means something subtly different (inactive, latent) rather than actively sleeping.