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.

---

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

---

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.

---

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 goal is to observe how vesicle dynamics may differ in affected neurons.

From Science Daily • Dec. 1, 2025

Specifically, those that involve dysfunction in synaptic vesicle recycling and neurotransmission, says Kravčenko.

From Science Daily • Dec. 3, 2024

They then used fluorescent dyes to inspect the mixtures and judge if vesicle formation had taken place.

From Science Daily • Feb. 29, 2024

As the food particle is consumed, it is encapsulated in a vesicle.

From Textbooks • Jan. 1, 2015

Some really are, and others closely resemble, the larval conditions of creatures higher in the scale, and the contracted vesicle with its channel bears resemblance to what is called the "water vascular system" of worms.

From Marvels of Pond-life A Year's Microscopic Recreations by Slack, Henry J.