[f. as prec. + GATE sb.1] A gate through which the water passes into a dock or the like at flood-time, and by which it is retained during the ebb.
1755. Johnson, Tidegate, a gate through which the tide passes into a bason.
1838. Civil Eng. & Arch. Jrnl., I. 410/2. As the embankments rise, the tide-gates will be arranged so as to regulate the quantity of water inside the bays.
1858. Simmonds, Dict. Trade, Tide-gate, the entrance gate of a dock.
