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a. Any of various devices that regulate the flow of gases, liquids, or loose materials through piping or through apertures by opening, closing, or obstructing ports or passageways.
b. The movable control element of such a device.
c. A device in a brass wind instrument that can be opened or closed to change the pitch by altering the length of the air column in the tube.
2. Anatomy A membranous structure in a hollow organ or passage, as in an artery or vein, that folds or closes to prevent the return flow of the body fluid passing through it.
3. Biology
a. A piece of shell covering or enclosing certain mollusks or other invertebrates, especially the single one of a univalve mollusk or one of the paired hinged ones of a bivalve mollusk or brachiopod.
b. One of the two siliceous halves of the cell wall of a diatom.
4. One of the pieces into which a plant part splits at maturity, especially a segment of a fruit capsule or of certain anthers.
5. Chiefly British An electron tube or a vacuum tube.
6. Archaic Either half of a double or folding door.
tr.v. valved, valv·ing, valves
1. To provide with a valve.
2. To control by means of a valve.

[Middle English, leaf of a door, from Latin valva; see wel- in Indo-European roots.]

valve′less adj.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.valved - (of brass instruments) having valvesvalved - (of brass instruments) having valves
References in periodicals archive ?
However, the functional life span of these conduits is relatively limited, and as a result, most patients with this type of defect may require multiple open heart surgeries to place new valved conduits as they grow over their lifetime.
Oftentimes, this type of defect requires open heart surgery early in life to implant a prosthetic valved conduit to establish adequate blood flow from the heart to the lungs.
The SJM Masters HP(TM) Valved Graft with Gelweave Valsalva(TM) technology, which is designed to simultaneously repair the damaged portion of the ascending aorta and replace the aortic valve during valve replacement surgery.