A mollusk having a shell consisting of two lateral plates or valves joined together by an elastic ligament at the hinge, which is usually strengthened by prominences called teeth. The shell is closed by the contraction of two transverse muscles attached to the inner surface, as in the clam, -- or by one, as in the oyster. See Mollusca.
- A mollusk, such as an oyster or a clam, that has a shell consisting of two hinged valves.
- Having a shell consisting of two hinged valves.
- Consisting of two similar separable parts.