DictionarybuoyFloating marker
noun / verb

buoy

BOO-ee/ˈbuːi/

A floating object used to mark a place in water.

A red buoy marks the edge of the shipping channel.

A red navigation buoy floats upright beside a submerged rocky shoal, with its mooring chain visibly descending to a seabed anchor block.
Etymology

The origin is disputed: a possible connection with “beacon” fits its signaling role, while a proposed link with “fetter, chain” refers to its being anchored to one spot.

In context

BoatUS2:41
When you see a buoy with black and white stripes that means there's an obstruction running from that buoy in toward shore, so make sure you go all the way around it.
Boat Navigation Basics: Buoys and Channel Markers | BoatUS

More examples

  • The life jacket buoyed him until help arrived.
  • Her encouraging message buoyed my spirits.
  • A new grant buoyed the struggling research program.

Forms

buoy · buoys · buoyed · buoying

buoyant adjective — Able to float or remain cheerful and hopeful.

Similar words

float
Anything that stays on the surface, while a buoy commonly marks a location.