tide

The tide is the regular rising and falling of sea levels caused by the moon.

Example: After getting the ship stuck on sand, the crew had to wait until high tide so it would refloat.

A tide may be something that rises and falls as if it were the sea.

Example: The politicians knew that one day the tide of public opinion would agree with them.

Tide is a period of time or a season; usually used with another word.

Example: She always looked forward to Whitsun tide.