What is the meaning of Buoy?

A float moored in water to mark a location, warn of danger, indicate a navigational channel or for other purposes

A life-buoy; a life preserver.

To keep afloat or aloft; used with up.

To support or maintain at a high level.

To mark with a buoy.

To maintain or enhance enthusiasm or confidence; to lift the spirits of.

Source: wiktionary.org