colloid

[ kol-oid ]

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. Compare aerosol, emulsion, gel, sol ⁴, suspension.
2. Medicine/Medical. a colloidal substance in the body, as a stored secretion or a cyst.

adjective

1. Physical Chemistry. colloidal.

colloid

/ ˈkɒlɔɪd /

noun

1. Also calledcolloidal solutioncolloidal suspension a mixture having particles of one component, with diameters between 10 ^–7and 10 ^–9metres, 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

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

/ 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

colloid

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.

Notes

Fog, paints, and foam rubber are colloids.

Other Words From

• non·colloid noun
• semi·colloid noun

Word History and Origins

Origin of colloid¹

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

Word History and Origins

Origin of colloid¹

C19: from Greek kolla glue + -oid

Example Sentences

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

From BBC

The TV presenter posted a video on Instagram to say she had been diagnosed with a rare type of benign tumour called a colloid cyst.

From BBC

“Our main finding out of this is that fat matters a lot,” Anwesha Sarkar, a professor of colloids and surfaces at the University of Leeds, told The Washington Post.

From Washington Post

He was placed into a medically induced coma after suffering a brain bleed and undergoing surgery to remove a colloid cyst that was still causing pressure on his brain.

From Fox News

For decades, researchers have attempted to create crystals with a diamond-like structure using small colloid particles.

From Nature