a life preserver consisting of a connected pair of inflatable bags that fit under a person's arms and provide buoyancy; used by children learning to swim
the basic unit of luminous intensity adopted under the Systeme International d'Unites; equal to 1/60 of the luminous intensity per square centimeter of a black body radiating at the temperature of 2,046 degrees Kelvin
examine eggs for freshness by holding them against a light
an electric railway operating below the surface of the ground (usually in a city); "in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'"