duck

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of various wild or domesticated waterbirds of the family Anatidae, characteristically having a broad flat bill, short legs, and webbed feet.
• noun A female duck.
• noun The flesh of a duck used as food.
• noun Slang A person, especially one thought of as peculiar.
• noun Chiefly British A dear.
• noun A durable, closely woven heavy cotton or linen fabric.
• noun Clothing made of duck, especially white trousers.
• noun An amphibious military truck used during World War II.
• noun An amphibious truck used in emergencies, as to evacuate flood victims.
• intransitive verb To lower quickly, especially so as to avoid something.
• intransitive verb To evade; dodge.
• intransitive verb To push (a person, for example) suddenly under water.
• intransitive verb In bridge, to deliberately play a card that is lower than (an opponent's card).
• intransitive verb To lower the head or body.
• intransitive verb To move swiftly, especially so as to escape being seen.
• intransitive verb To submerge the head or body briefly in water.
• intransitive verb To evade a responsibility or obligation. Often used with out:
• intransitive verb In bridge, to lose a trick by deliberately playing lower than one's opponent.
• noun A quick lowering of the head or body.
• noun A plunge under water.

from The Century Dictionary.

• noun A diving inclination of the head.
• To plunge the head or the whole body into water and immediately withdraw; make a dip.
• To nod or bob the head suddenly; bow.
• Hence To give way; yield; cringe.
• To dip or plunge in water and immediately withdraw: as, to duck a witch or a scold.
• To lower or bend down suddenly, as in dodging a missile or an obstacle, or in saluting awkwardly: as, to duck the head.
• noun A sweetheart; a darling: a word of endearment, fondness, or admiration. It is sometimes also applied to things: as, a duck of a bonnet.
• noun A lamellirostral natatorial bird of the family Anatidœ and subfamily Anatinœ or Fuligulinœ (which see).
• noun The female duck, as distinguished from the male, or drake (which see).
• noun Some webfooted bird likened to or mistaken for a duck: as, the cobbler's-awl duck (that is, the avoset).
• noun One of the stones used in playing the game of duck on drake.
• noun The velvet scoter.
• noun The surf-scoter.
• noun The ruddy duck.
• noun The female mallard.
• noun The female pintail.
• noun The harlequin.
• noun The hooded merganser. Also called water-pheasant.
• noun Specifically— The wood-duck (which see). See Aix.
• noun The garganey or summer tcal, Querquedula circia.
• noun Hence— To handle or use a thing recklessly; scatter; squander; throw into confusion: with with or of.
• noun The wood-duck or summer duck, which breeds in trees.
• noun The hooded merganser: so called from breeding in trees.
• In bridge, to lead a suit from the dealer or the dummy hand, and make no attempt to win the trick third hand, even when able to do so. See underplay.
• noun A strong linen fabric simply woven without twill, lighter than canvas, and used for small sails, sails for pleasure-boats, and for men's wear. Duck is usually white or unbleached, but is sometimes made in plain colors.
• noun A cotton fabric sometimes considered the second grade, for strength and durability, after double-warp (which see, under warp).
• noun In cricket, no score; zero: short for duck's-egg (which see).

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To go under the surface of water and immediately reappear; to dive; to plunge the head in water or other liquid; to dip.
• intransitive verb To drop the head or person suddenly; to bow.
• noun (Zool.) Any bird of the subfamily Anatinæ, family Anatidæ.