from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A tide gate, designed to protect marshland, so constructed as to let out water at low tide, but to prevent an influx of water at high tide.
from The Century Dictionary and Cyclopedia
- n. A dam to prevent the tide from overflowing a marsh.
- To improve (a tidal river or stream) and prevent the tidal overflow of its marshes and tidal meadows by placing tide-gates at its mouth.
Borrowing from Acadian French aboideau (Wiktionary)