reef
US /riːf/
UK /riːf/

1.
1.
reven
reduce the area of (a sail) by folding or rolling part of it and securing it to the spar or mast
:
•
The sailors had to reef the sails as the storm approached.
De zeelieden moesten de zeilen reven toen de storm naderde.
•
We decided to reef the main sail to reduce speed.
We besloten het grootzeil te reven om de snelheid te verminderen.