periodic event, recurrent event - an event that recurs at intervals

high tide, high water, highwater - the tide when the water is highest

low tide, low water - the lowest (farthest) ebb of the tide

ebbtide - the tide while water is flowing out

rising tide, flood tide - the occurrence of incoming water (between a low tide and the following high tide)

lee tide, leeward tide - a tide that runs in the same direction as the wind is blowing; "a leeward tide is dangerous for small boats"

slack tide, slack water - the occurrence of relatively still water at the turn of the (low) tide

tidal current, tidal flow - the water current caused by the tides

rip current, riptide - a strong surface current flowing outwards from a shore

undertide, undercurrent - a current below the surface of a fluid

variation, fluctuation - an instance of change; the rate or magnitude of change

period, period of time, time period - an amount of time; "a time period of 30 years"; "hastened the period of time of his recovery"; "Picasso's blue period"

course, flow, run, feed - move along, of liquids; "Water flowed into the cave"; "the Missouri feeds into the Mississippi"

float - set afloat; "He floated the logs down the river"; "The boy floated his toy boat on the pond"

bridge over, tide over, keep going - suffice for a period between two points; "This money will keep us going for another year"

be adrift, drift, float, blow - be in motion due to some air or water current; "The leaves were blowing in the wind"; "the boat drifted on the lake"; "The sailboat was adrift on the open sea"; "the shipwrecked boat drifted away from the shore"