n. any of numerous predaceous aquatic insects of the family Notonectidae (such as Notonecta undulata) that swim on their backs and may inflict painful bites; -- also called boat bug. [ RHUD ] [ WordNet 1.5 +PJC ]

a. (Zool.) 1. Swimming in the open sea; -- said of certain marine animals. [ 1913 Webster ]

2. (Zoology) able to swim about; not attached to a stationary object; -- of aquatic animals. [ wns=1 ]
Syn. -- unattached. [ WordNet 1.5 ]

v. i. [ imp. Swam r Swum p. p. Swum; p. pr. & vb. n. Swimming. ] [ AS. swimman; akin to D. zwemmen, OHG. swimman, G. schwimmen, Icel. svimma, Dan. swömme, Sw. simma. Cf. Sound an air bladder, a strait. ] 1. To be supported by water or other fluid; not to sink; to float; as, any substance will swim, whose specific gravity is less than that of the fluid in which it is immersed. [ 1913 Webster ]

2. To move progressively in water by means of strokes with the hands and feet, or the fins or the tail. [ 1913 Webster ]

Leap in with me into this angry flood,
And swim to yonder point. Shak. [ 1913 Webster ]

3. To be overflowed or drenched. Ps. vi. 6. [ 1913 Webster ]

Sudden the ditches swell, the meadows swim. Thomson. [ 1913 Webster ]

4. Fig.: To be as if borne or floating in a fluid. [ 1913 Webster ]

[ They ] now swim in joy. Milton. [ 1913 Webster ]

5. To be filled with swimming animals. [ Obs. ] [ 1913 Webster ]

[ Streams ] that swim full of small fishes. Chaucer. [ 1913 Webster ]

v. t. 1. To pass or move over or on by swimming; as, to swim a stream. [ 1913 Webster ]

Sometimes he thought to swim the stormy main. Dryden. [ 1913 Webster ]

2. To cause or compel to swim; to make to float; as, to swim a horse across a river. [ 1913 Webster ]

3. To immerse in water that the lighter parts may float; as, to swim wheat in order to select seed. [ 1913 Webster ]

n. 1. The act of swimming; a gliding motion, like that of one swimming. B. Jonson. [ 1913 Webster ]

2. The sound, or air bladder, of a fish. [ 1913 Webster ]

3. A part of a stream much frequented by fish. [ Eng. ] [ 1913 Webster ]

Swim bladder, an air bladder of a fish. --
To be in the swim, to be in a favored position; to be associated with others in active affairs. [ Colloq. ] [ 1913 Webster ]

v. i. [ OE. swime dizziness, vertigo, AS. swīma; akin to D. zwijm, Icel. svimi dizziness, svina to subside, svīa to abate, G. schwindel dizziness, schwinden to disappear, to dwindle, OHG. swīnan to dwindle. Cf. Squemish, Swindler. ] To be dizzy; to have an unsteady or reeling sensation; as, the head swims. [ 1913 Webster ]

n. [ Etymol. uncertain. ] A moaning or sighing sound or noise; a sough. [ Obs. ] Chaucer. [ 1913 Webster ]

n. 1. One who swims. [ 1913 Webster ]

2. (Far.) A protuberance on the leg of a horse. [ 1913 Webster ]

3. (Zool.) A swimming bird; one of the natatores. [ 1913 Webster ]

Little swimmer (Zool.), a phalarope. [ 1913 Webster ]

n. (Zool.) One of a series of flat, fringed, and usually bilobed, appendages, of which several pairs occur on the abdominal somites of many crustaceans. They are used as fins in swimming. [ 1913 Webster ]

a. 1. That swims; capable of swimming; adapted to, or used in, swimming; as, a swimming bird; a swimming motion. [ 1913 Webster ]

2. Suffused with moisture; as, swimming eyes. [ 1913 Webster ]

Swimming bell (Zool.), a nectocalyx. See Illust. under Siphonophora. --
Swimming crab (Zool.), any one of numerous species of marine crabs, as those of the family Protunidae, which have some of the joints of one or more pairs of legs flattened so as to serve as fins. [ 1913 Webster ]

n. The act of one who swims. [ 1913 Webster ]

a. [ From Swim to be dizzy. ] Being in a state of vertigo or dizziness; as, a swimming brain. [ 1913 Webster ]

n. Vertigo; dizziness; as, a swimming in the head. Dryden. [ 1913 Webster ]

adv. In an easy, gliding manner, as if swimming; smoothly; successfully; prosperously. [ 1913 Webster ]

n. Act or state of swimming; suffusion. “A swimmingness in the eye.” Congreve. [ 1913 Webster ]