bladder

American Heritage® Dictionary of the English Language, Fourth Edition

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

Century Dictionary and Cyclopedia

1. n. 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. Such a vesicle is specially characteristic of mammals, its size and shape varying with the species. Its cavity is primitively that of the allantois. It is lined with mucous membrane, is more or less invested with peritoneum, and is supplied with vessels and nerves.
2. n. Any similar receptacle, sac, or vesicle, commonly distinguished by a qualifying prefix. See air-bladder, brain-bladder, gall-bladder, swim-bladder.
3. n. Any vesicle, blister, bleb, blain, or pustule containing fluid or air.
4. n. In botany: A hollow membranous appendage on the leaves of Utricularia, filled with air and floating the plant.
5. n. A cellular expansion of the substance of many algæ filled with air. See cut under air-cell.
6. n. Anything inflated, empty, or unsound: as, “bladders of philosophy,”
7. To put up in a bladder: as, bladdered lard.
8. To puff up; fill, as with wind.
9. n. A membranous inflated fruit, as that of Kœlreuteria or the pericarp of Physalis.

Wiktionary

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

GNU Webster's 1913

1. n. (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.
2. n. Any vesicle or blister, especially if filled with air, or a thin, watery fluid.
3. n. (Bot.) A distended, membranaceous pericarp.
4. n. Anything inflated, empty, or unsound.
5. v. obsolete To swell out like a bladder with air; to inflate.
6. v. To put up in bladders.

WordNet 3.0

1. n. a distensible membranous sac (usually containing liquid or gas)
2. n. a bag that fills with air