colloid

American  

[kol-oid] / ˈkɒl ɔɪd /

noun

1. Physical Chemistry. a substance made up of a system of particles with linear dimensions in the range of about 10 −7 to 5 × 10 −5 centimeters dispersed in a continuous gaseous, liquid, or solid medium whose properties depend on the large specific surface area. The particles can be large molecules like proteins, or solid, liquid, or gaseous aggregates and they remain dispersed indefinitely.

2. Medicine/Medical. a colloidal substance in the body, as a stored secretion or a cyst.

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adjective

1. Physical Chemistry. colloidal.

colloid British  

/ ˈkɒlɔɪd /

noun

1. Also called: colloidal solution.   colloidal suspension.  a mixture having particles of one component, with diameters between 10 ^–7 and 10 ^–9 metres, suspended in a continuous phase of another component. The mixture has properties between those of a solution and a fine suspension

2. the solid suspended phase in such a mixture

3. obsolete a substance that in solution does not penetrate a semipermeable membrane Compare crystalloid

4. physiol a gelatinous substance of the thyroid follicles that holds the hormonal secretions of the thyroid gland

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adjective

1. pathol of or relating to the gluelike translucent material found in certain degenerating tissues

2. of, denoting, or having the character of a colloid

colloid Scientific  

/ kŏl′oid′ /

1. A mixture in which very small particles of one substance are distributed evenly throughout another substance. The particles are generally larger than those in a solution, and smaller than those in a suspension. Paints, milk, and fog are colloids.

2. Compare solution suspension

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colloid Cultural  

1. A substance made up of particles that are larger than most molecules; these particles do not actually dissolve in substances but stay suspended in them.

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Discover More

Fog, paints, and foam rubber are colloids.

Other Word Forms

• noncolloid
  noun
• semicolloid
  noun

Etymology

Origin of colloid

First recorded in 1840–50; from Greek kóll(a) “glue” + -oid

Example Sentences

"Our far-reaching theory encompasses all systems evidencing such transverse interactions. Conceivable applications range from colloid research to biology," declares co-author Dr. Michael te Vrugt, Assistant Professor at the University of Mainz.

From Science Daily • Oct. 21, 2025

Celebrity Davina McCall's recent revelation that a colloid cyst in her brain was picked up on a routine screening has focused attention on how such scans can detect minor abnormalities.

From BBC • Dec. 4, 2024

"But it turned out I had a benign brain tumour called a colloid cyst, which is very rare - three in a million."

From BBC • Nov. 18, 2024

The particles of a colloid remain dispersed and do not settle due to gravity,

From Textbooks • Feb. 14, 2019

There is no real difference between the passage of a solution through an osmotic membrane and its diffusion through a colloid.

From The Mechanism of Life by Leduc, Stéphane