colloid

1 of 2

noun

col·​loid ˈkä-ˌlȯid 

1

: a gelatinous or mucinous substance found normally in the thyroid and also in diseased tissue

2

a

: a substance that consists of particles dispersed throughout another substance which are too small for resolution (see resolution sense 5a) with an ordinary light microscope but are incapable of passing through a semipermeable membrane

b

: a mixture consisting of a colloid together with the medium in which it is dispersed

smoke is a colloid

colloidal

kə-ˈlȯi-dᵊl 

kä-

adjective

colloidally adverb

colloidal

2 of 2

adjective

col·​loi·​dal kə-ˈlȯi-dᵊl 

(ˈ)kä-¦lȯi-

: of, relating to, or having the properties of a colloid

colloidal state

colloidal graphite

colloidality

¦kä-lȯi-¦da-lə-tē

noun

plural -es

colloidally adverb

Examples of colloid in a Sentence

Recent Examples on the Web

Noun

When later soaked in a developing agent, some particles in the colloid mixture are removed, while others remain. — Scott Gilbertson, Wired News, 15 Nov. 2025

The safety effect comes from a colloid, a suspension of tiny solid particles in a liquid. — Bojan Stojkovski, Interesting Engineering, 6 Sep. 2025

On Wednesday, May 14, the Hollywood Medium star, 29, revealed on Instagram that he'd been diagnosed with a colloid tumor near the center of his brain, which had required surgery to remove it. — Becca Longmire, People.com, 15 May 2025

In colloids as in biofilms, these interactions are governed by two opposing forces. — Carrie Arnold, Quanta Magazine, 21 Apr. 2025

Healthcare providers use colloid fluids for people with severe dehydration or fluid loss. — Rachael Zimlich, Bsn, Rn, Verywell Health, 23 Sep. 2024

Bluing is not a dye, but rather a colloid of blue iron salt suspended in water. — Jolie Kerr, Better Homes & Gardens, 18 Sep. 2024

Shining a laser light through a gold colloid mixture produces the Faraday-Tyndall Effect. — Jennifer Ouellette, Ars Technica, 26 Dec. 2023

Word History

Etymology

Noun

noun derivative of colloid, adjective, "pertaining to colloidal tissue," probably borrowed from New Latin colloïdēs, literally, "gluelike," from Greek kólla "glue" + New Latin -oïdēs -oid entry 2 — more at protocol

First Known Use

Noun

circa 1852, in the meaning defined at sense 1

Rhymes for colloid

• amygdaloid

Kids Definition

colloid

noun

col·​loid ˈkäl-ˌȯid 

: a very finely divided substance which is scattered throughout another substance

also : a mixture consisting of such a substance together with the substance in which it is scattered (as in smoke, gelatin, or marshmallow)

colloidal

kə-ˈlȯid-ᵊl 

kä-

adjective

Medical Definition

colloid

noun

col·​loid ˈkäl-ˌȯid 

1

: a gelatinous or mucinous substance found in tissues in disease or normally (as in the thyroid)

2

a

: a substance consisting of particles that are dispersed throughout another substance and are too small for resolution with an ordinary light microscope but are incapable of passing through a semipermeable membrane

b

: a mixture (as smoke) consisting of a colloid together with the medium in which it is dispersed

colloidal

kə-ˈlȯid-ᵊl, kä- 

adjective

colloidally

-ᵊl-ē 

adverb