\Blad"der\, n. [OE. bladder, bleddre, AS. bl?dre,
bl?ddre; akin to Icel. bla?ra, SW. bl["a]ddra, Dan. bl[ae]re,
D. blaar, OHG. bl[=a]tara the bladder in the body of animals,
G. blatter blister, bustule; all fr. the same root as AS.
bl[=a]wan, E. blow, to puff. See {Blow} to puff.]
1. (Anat.) A bag or sac in animals, which serves as the
   receptacle of some fluid; as, the urinary bladder; the
   gall bladder; -- applied especially to the urinary
   bladder, either within the animal, or when taken out and
   inflated with air.
2. Any vesicle or blister, especially if filled with air, or
   a thin, watery fluid.
3. (Bot.) A distended, membranaceous pericarp.
4. Anything inflated, empty, or unsound. ``To swim with
   bladders of philosophy.'' --Rochester.
{Bladder nut}, or {Bladder tree} (Bot.), a genus of plants
   ({Staphylea}) with bladderlike seed pods.
{Bladder pod} (Bot.), a genus of low herbs ({Vesicaria}) with
   inflated seed pods.
{Bladdor senna} (Bot.), a genus of shrubs ({Colutea}), with
   membranaceous, inflated pods.
{Bladder worm} (Zo["o]l.), the larva of any species of
   tapeworm ({T[ae]nia}), found in the flesh or other parts
   of animals. See {Measle}, {Cysticercus}.
{Bladder wrack} (Bot.), the common black rock weed of the
   seacoast ({Fucus nodosus} and {F. vesiculosus}) -- called
   also {bladder tangle}. See {Wrack}.

\Blad"der\, v. t. [imp. & p. p. {Bladdered}; p. pr. &
vb. n. {Bladdering}.]
1. To swell out like a bladder with air; to inflate. [Obs.]
   --G. Fletcher.
2. To put up in bladders; as, bladdered lard.