[1] : The Collaborative International Dictionary of English v.0.48

swim \swim\, 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
see also:
swim bladder to be in the swim 

[2] : WordNet (r) 2.0

swim bladder
     n : an air-filled sac near the spinal column in many fishes that
         helps maintain buoyancy syn: air bladder
see also:
air bladder 

Swim Bladder >> S Words
Swim Bladder, definition of term: Swim Bladder
swim+bladder_pag1.html

Bladder >> B Words
Bladder, definition of term: Bladder
bladder_pag1.html

Swim >> S Words
Swim, definition of term: Swim
swim_pag1.html

Bladder Wrack >> B Words
Bladder Wrack, definition of term: Bladder Wrack
bladder+wrack_pag1.html

Urinary Bladder >> U Words
Urinary Bladder, definition of term: Urinary Bladder
urinary+bladder_pag1.html

Gall Bladder >> G Words
Gall Bladder, definition of term: Gall Bladder
gall+bladder_pag1.html

Air Bladder >> A Words
Air Bladder, definition of term: Air Bladder
air+bladder_pag1.html