bivalve

American  

[bahy-valv] / ˈbaɪˌvælv /

noun

1. Also called lamellibranch. Zoology. any mollusk, as the oyster, clam, scallop, or mussel, of the class Bivalvia, having two shells hinged together, a soft body, and lamellate gills.

---

adjective

1. Botany. having two valves, as a seedcase.

2. Zoology. having two shells, usually united by a hinge.

3. having two similar parts hinged together.

bivalve British  

/ ˈbaɪˌvælv /

noun

1. Also: pelecypod, lamellibranch. any marine or freshwater mollusc of the class Pelecypoda (formerly Bivalvia or Lamellibranchia ), having a laterally compressed body, a shell consisting of two hinged valves, and gills for respiration. The group includes clams, cockles, oysters, and mussels

---

adjective

1. Also: pelecypod, lamellibranch. of, relating to, or belonging to the Pelecypoda

2. Also: bivalvate. biology having or consisting of two valves or similar parts

   a bivalve seed capsule

bivalve Scientific  

/ bī′vălv′ /

1. Any of various mollusks of the class Bivalvia, having a shell consisting of two halves hinged together. Clams, oysters, scallops, and mussels are bivalves. The class Bivalvia is also called Pelecypoda, and was formerly called Lamellibranchia.

2. Compare univalve

---

Other Word Forms

• bivalvular
  adjective

---

Etymology

Origin of bivalve

First recorded in 1670–80; bi- ¹ + valve

---

Explanation

A bivalve is a sea creature with two shells, one on top and one underneath, connected by a kind of hinge. Mussels and clams are bivalves; snails and abalone are not. Bivalves are soft on the inside with a very hard, protective shell on the outside. You know you're looking at a bivalve when you see two distinct halves of that shell, which can swing shut like a door when the animal perceives danger. Oysters fall into this category, and so do scallops. Bivalve, literally "two valves," comes from the Latin valva, "section of a folding door."

Example Sentences

See Examples For:

bivalve

This marks only the second bivalve species ever documented entirely through non-invasive micro-CT scanning.

From Science Daily ● Nov. 2, 2025

He put the wee bivalve in a petri dish and asked a colleague to set it aside.

From New York Times ● Feb. 6, 2024

The shells belonged to an assortment of tiny seafloor creatures, including small clams; bivalve crustaceans called ostracods; cone-shaped animals known as hyoliths; and stylophorans, oddly shaped precursors to starfish.

From Scientific American ● Sep. 28, 2023

You say bivalve and deep water coral reefs grow over the rigs' legs, yet reefs are otherwise hard to come by in the Northern Gulf.

From Salon ● Sep. 26, 2023

But the ominousness of it: that long red slit between a dark sky and a dark Ionian sea, terrible old bivalve which has held life between its lips so long.

From Sea and Sardinia by D. H. (David Herbert) Lawrence

Random Word

Spin the wheel and learn a new word!

---