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 6a) 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
colloidally adverb

Examples of colloid in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
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

Word History

Etymology

International Scientific Vocabulary coll- + -oid

First Known Use

circa 1852, in the meaning defined at sense 1

Time Traveler
The first known use of colloid was circa 1852

Dictionary Entries Near colloid

Cite this Entry

“Colloid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/colloid. Accessed 30 Dec. 2024.

Kids Definition

: 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)

Medical Definition

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

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