one who, or that which, skims; esp., a utensil with which liquids are skimmed.-any species of longwinged marine birds of the genus rhynchops, allied to the terns, but having the lower mandible compressed and much longer than the upper one. these birds fly rapidly along the surface of the water, with the lower mandible immersed, thus skimming out small fishes. the american species (r. nigra) is common on the southern coasts of the united states. called also scissorbill, and shearbill.-any one of several large bivalve shells, sometimes used for skimming milk, as the sea clams, and large scallops.