windless

Windless is an adjective meaning without wind or with no appreciable wind. In weather reporting and nautical contexts, it describes conditions where surface air is nearly still. A windless day often yields smooth, glassy water and very little motion of leaves or smoke.

Among sailors, windless conditions cause a vessel under sail to make little to no headway; the ship is becalmed. The term becalmed is more precise for the sailing situation, but windless is used to describe the broader environmental condition.

In meteorology, windless conditions commonly occur under high-pressure systems and in subtropical regions during certain seasons, when air is relatively stable and horizontal wind speeds fall to a few knots or less. The phrase is also used historically to describe the doldrums near the equator, where winds can be absent for days or weeks.

Originating from the combination of wind and the suffix -less, windless conveys the absence of wind. The word is largely specialized to weather and nautical discourse and is less common in everyday speech outside those domains.