bladder

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

• noun Anatomy Any of various distensible membranous sacs, such as the urinary bladder or the swim bladder, that serve as receptacles for fluid or gas.
• noun Medicine A blister, pustule, or cyst filled with fluid or air; a vesicle.
• noun An item resembling one of the membranous sacs in animals.
• noun Botany Any of various hollow or inflated saclike organs or structures, such as the floats of certain seaweeds or the specialized traps of bladderworts.

from The Century Dictionary.

• noun A thin, elastic, highly distensible and contractile muscular and membranous sac forming that portion of the urinary passages in which urine, constantly secreted by the kidneys, is retained until it is discharged from the body.
• noun Any similar receptacle, sac, or vesicle, commonly distinguished by a qualifying prefix. See air-bladder, brain-bladder, gall-bladder, swim-bladder.
• noun Any vesicle, blister, bleb, blain, or pustule containing fluid or air.
• noun In botany: A hollow membranous appendage on the leaves of Utricularia, filled with air and floating the plant.
• noun A cellular expansion of the substance of many algæ filled with air. See cut under air-cell.
• noun Anything inflated, empty, or unsound: as, “bladders of philosophy,”
• noun A membranous inflated fruit, as that of Kœlreuteria or the pericarp of Physalis.
• To put up in a bladder: as, bladdered lard.
• To puff up; fill, as with wind.

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

• noun (Anat.) A bag or sac in animals, which serves as the receptacle of some fluid; ; -- applied especially to the urinary bladder, either within the animal, or when taken out and inflated with air.
• noun Any vesicle or blister, especially if filled with air, or a thin, watery fluid.
• noun (Bot.) A distended, membranaceous pericarp.
• noun Anything inflated, empty, or unsound.
• noun (Bot.) a genus of plants (Staphylea) with bladderlike seed pods.
• noun (Bot.) a genus of low herbs (Vesicaria) with inflated seed pods.
• noun (Bot.) a genus of shrubs (Colutea), with membranaceous, inflated pods.
• noun (Zoöl.) the larva of any species of tapeworm (Tænia), found in the flesh or other parts of animals. See Measle, Cysticercus.
• noun (Bot.) the common black rock weed of the seacoast (Fucus nodosus and Fucus vesiculosus) -- called also bladder tangle. See Wrack.
• transitive verb obsolete To swell out like a bladder with air; to inflate.
• transitive verb To put up in bladders.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun zoology A flexible sac that can expand and contract and that holds liquids or gases.
• noun anatomy Specifically, the urinary bladder.
• noun botany A hollow, inflatable organ of a plant.
• noun The inflatable bag inside various balls used in sports, such as footballs and rugby balls.
• noun A sealed, plastic bag that contains wine and is usually packaged in a cask.
• verb To swell out like a bladder with air; to inflate.
• verb transitive To store or put up in bladders.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a distensible membranous sac (usually containing liquid or gas)
• noun a bag that fills with air