sasse
A sluice or lock, as in a river or canal, to make it more navigable.
obsolete
Thence with him to the Trinity-house to dinner; where Sir Richard Brown, one of the clerkes of the Council, and who is much concerned against Sir N. Crisp's project of making a great sasse in the King's lands about Deptford, to be a wett-dock to hold 200 sail of ships.
Where it comes from
Dutch sas, from French sas (“the basin of a waterfall”).
Adapted from the Wiktionary entry sasse (CC BY-SA 4.0).