windless

/ˈwɪndləs/
adjective
  1. Having no wind; calm and still.
    • They enjoyed a windless afternoon on the beach, with the ocean as smooth as glass.
    • The lake was perfectly windless, reflecting the mountains like a mirror.
    • The windless conditions made the sailboat drift aimlessly in the harbor.
Antonyms
What does "windless" mean? | whatsthatwordmean | whatsthatwordmean