Apnea

Etymology

From Greek “a-” (without) and “pnoia” (breath), from “pnein” (to breathe) — literally “without breath.” The same root gives “dyspnea” (labored breathing) and echoes in “pneuma,” the ancient word for breath and spirit. The bare Greek names exactly what happens: for a moment, the breathing simply is not there.

noun · /AP-nee-uh/
A temporary stop in breathing, most commonly during sleep.
What it names
A hidden and surprisingly common problem — repeated pauses in breathing through the night — that leaves people exhausted by day without ever knowing why.
Example
His wife noticed he kept stopping breathing in his sleep, and a study confirmed sleep apnea was behind his constant fatigue.
Related idea
Apnea is the stopping of breath entirely; dyspnea is breathing that continues but with difficulty. Both concern the breath, yet one is an absence and the other a struggle — and apnea during sleep is dangerous precisely because the sufferer never witnesses it.