euripus
A strait; a narrow tract of water, where the tide or a current flows and reflows with violence, like the ancient firth of this name between Euboea and Boeotia.
A flux and reflux.
They have ordained that the provision of this establishment might be as stable as the earth on which it stands , and should not fluctuate with the Euripus of funds and actions
Where it comes from
From Latin eurīpus, from Ancient Greek εὔριπος (eúripos); from εὖ (eû, “well”) + ῥιπή (rhipḗ, “rushing motion”).
Adapted from the Wiktionary entry euripus (CC BY-SA 4.0).