late 14c., from Old French sompnolence (14c.), from Latin somnolentia "sleepiness," from somnolentus, from somnus "sleep" (see somnus). Related: Somnolency.
mid-15c., sompnolent, from Old French sompnolent (Modern French somnolent) or directly from Latin somnolentus "sleepy, drowsy," from somnus "sleep" (see Somnus). Respelled 17c. on Latin model.
somnolence som·no·lence (sŏm'nə-ləns)
n.
A state of drowsiness; sleepiness.
A condition of semiconsciousness approaching coma.
somnolent som·no·lent (sŏm'nə-lənt)
adj.
Drowsy; sleepy.
Inducing or tending to induce sleep; soporific.
In a condition of incomplete sleep; semicomatose.