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

The TV presenter, 57, underwent surgery in November after a colloid cyst was found during a health check-up as part of her menopause advocacy work.

From BBC • Mar. 8, 2025

"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

In the absence of iodine, this is not converted to thyroid hormone, and colloid begins to accumulate more and more in the thyroid gland, leading to goiter.

From Textbooks • Jun. 9, 2022

The colloid appearances due to the amyloid degeneration of cells are of the greatest clinical importance from their frequent occurrence and the gravity of the symptoms connected with their presence.

From A System of Practical Medicine by American Authors, Vol. I Volume 1: Pathology and General Diseases by Various