vesicle

American  

[ves-i-kuhl] / ˈvɛs ɪ kəl /

noun

1. a small sac or cyst.

2. Biology. a small bladderlike cavity, especially one filled with fluid.

3. Pathology. a circumscribed elevation of the epidermis containing serous fluid; blister.

4. Geology. a small, usually spherical cavity in a rock or mineral, formed by expansion of a gas or vapor before the enclosing body solidified.

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vesicle British  

/ vɛˈsɪkjʊlə, ˈvɛsɪkəl /

noun

1. pathol

   1. any small sac or cavity, esp one containing serous fluid

   2. a blister

2. geology a rounded cavity within a rock formed during solidification by expansion of the gases present in the magma

3. botany a small bladder-like cavity occurring in certain seaweeds and aquatic plants

4. any small cavity or cell

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vesicle Scientific  

/ vĕs′ĭ-kəl /

1. A small fluid-filled sac in the body.

2. A membrane-bound sac in eukaryotic cells that stores or transports the products of metabolism in the cell and is sometimes the site for the breaking down of metabolic wastes. Vesicles bulge out and break off from the endoplasmic reticulum and the Golgi apparatus. Vesicles get their energy for mobility from ATP. Lysosomes and peroxisomes are vesicles.

3. A small cavity formed in volcanic rock by entrapment of a gas bubble during solidification.

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Other Word Forms

• vesicular
  adjective
• vesicularly
  adverb

Etymology

Origin of vesicle

First recorded in 1570–80, vesicle is from the Latin word vēsīcula little bladder. See vesica, -ule

Explanation

A vesicle is a tiny cavity or sac in an animal, even a human animal. Vesicles are like bladders or blisters, and they usually hold fluid. They’re really small. Vesicle is from the Latin word vesicular for “bladder or blister.” A vesicle is like a little bladder, because it's a fluid-filled sac in an animal, like little organic bags of liquid. The other key element of a vesicle is that it's small — vesicles tend to be extremely tiny. They’re so small, that some are inside cells, as membrane-bound spheres that are separate from the surrounding cytoplasm. That’s tiny!

Example Sentences

The cell then pulls this vesicle inward, where the coat dissolves and releases the virus.

From Science Daily • Dec. 4, 2025

The findings speak to the value of using universal adult donor cells to create these extracellular vesicle therapies, the researchers said, because they don't carry the risk of generating an immune response.

From Science Daily • May 16, 2024

Similarly, when they blocked synaptic vesicle production by hair follicle cells, they were no longer able to signal to the sensory nerves.

From Science Daily • Oct. 27, 2023

The vesicle fuses with a lysosome, and proteins inside the lysosome digest the food particle.

From Textbooks • Jan. 1, 2015

The anterior epithelium of the lens vesicle remains, but from the posterior the lens fibres are developed and these gradually fill up the cavity.

From Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 1 "Evangelical Church Conference" to "Fairbairn, Sir William" by Various