(tīd) noun
1. The periodic rise and fall of the surface of the ocean, and of the waters connected with the ocean, caused by the attraction of moon and sun. In each lunar day of 24 hours and 51 minutes there are two high tides and two low tides, alternating at equal intervals of flood and ebb. Spring tides are high tides above the average, occurring when the moon is new or full; neap tides are high tides below the average, occurring when the moon is in the first or third quarter. See FLOOD, EBB.
2. Anything that comes like the tide at flood; the time at which something is most flourishing.
3. The natural drift or tendency of events; also, a current; stream.
4. Season; time; especially, a season of the ecclesiastical year: used chiefly in composition and in the phrase time and tide: Christmastide.
5. Archaic A suitable or favorable occasion; opportunity. See synonyms under STREAM.
—v. tid·ed, tid·ing v.i.
1. To ebb and flow like the tide.
2. To float with the tide.
—v.t.
3. To carry or help like a boat buoyed up by the tide: Charity tided us over the depression.
4. To surmount; survive; endure, as a difficulty: with over: to tide over hard times. [OE tīd a period, season]
—tide′less adjective

(tīd) v.i. Archaic
To betide; happen. [OE tīdan]