windsail
/ˈwɪndseɪl/Definitions
1. noun
A triangular or quadrilateral sail set in front of a mast, used to catch the wind when a boat is becalmed or in light airs.
“The sailors decided to deploy the windsail to catch the gentle breeze.”
2. verb
To sail with the wind, especially in a gentle or favorable breeze.
“The boat will windsail across the lake this weekend.”