emulsion
Americannoun
-
emulsions
plural
-
Physical Chemistry. any colloidal suspension of a liquid in another liquid.
-
such a suspension used in cosmetics.
-
Pharmacology. a liquid preparation consisting of two completely immiscible liquids, one of which, as minute globules coated by a gum or other mucilaginous substance, is dispersed throughout the other: used as a means of making a medicine palatable.
-
Photography. a composition sensitive to some or all of the actinic rays of light, consisting of one or more of the silver halides suspended in gelatin, applied in a thin layer to one surface of a film or the like.
noun
-
photog a light-sensitive coating on a base, such as paper or film, consisting of fine grains of silver bromide suspended in gelatine
-
chem a colloid in which both phases are liquids
an oil-in-water emulsion
-
Also called: emulsion paint. a type of paint in which the pigment is suspended in a vehicle, usually a synthetic resin, that is dispersed in water as an emulsion. It usually gives a mat finish
-
pharmacol a mixture in which an oily medicine is dispersed in another liquid
-
any liquid resembling milk
Usage
What does emulsion mean? An emulsion is a mixture of two liquids that don’t fully combine. An emulsion may look like a single liquid, but it’s made up of particles of one liquid distributed throughout another liquid. For example, if you whisk together oil and water, it forms an emulsion in which small droplets of oil are suspended in the water, but the two liquids aren’t fully blended together (as they would be if you stirred together water and vinegar, for example). In technical chemistry terms, an emulsion is a colloidal suspension in which the substances mixed together are both liquids. Both colloids and suspensions involve particles of one substance distributed in another without being dissolved. The word emulsion is used in a variety of contexts, including pharmacology, cooking, and photography. In cooking, emulsions are made by blending two liquids or liquid-like ingredients into a smooth consistency. Salad dressings called vinaigrettes are typically emulsions of oil and vinegar. The word emulsion is used in a more specific way in photography to refer to a light-sensitive coating (consisting of a chemical suspended in gelatine) that’s applied to paper or film. The verb emulsify means to form an emulsion. Example: To properly make an emulsion of oil and vinegar, you have to whisk very hard to separate the oil into tiny droplets, or else the two liquids will separate.
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of emulsion
1605–15; < New Latin ēmulsiōn- (stem of ēmulsiō ), equivalent to Latin ēmuls ( us ) milked out ( ē- e- 1 + mulsus, past participle of mulgēre to milk) + -iōn- -ion
Explanation
Ever notice the separate layers of oil and vinegar in salad dressing? Give the bottle a shake and those layers combine in a process called emulsion or the combination of liquids that don't dissolve into each other. Emulsion comes from the Latin mulgere meaning to "milk out." Seems strange, doesn't it? But in the early seventeenth century, the term was used to describe the milky liquid that result from crushing almonds in water. Think of natural peanut butter and how it separates with a thick layer of oil on top. When you stir it with a long spoon, that's the process of emulsion, or a combination of two liquids that don't dissolve into each other.
Vocabulary lists containing emulsion
A Culinary Vocabulary Sampler
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
The Grapes of Wrath
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
The Golden Compass
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
The pitted road surface was scalped by a 30-tonne machine planer and the debris swept out before a bitumen emulsion binder was sprayed ahead of the laying of fresh asphalt.
From BBC ● Jun. 10, 2026
Three of the four said they disliked cold lay repairs and that a properly laid hot fill option, done to the proper depth and with a tack coat emulsion, should last years.
From BBC ● Jun. 10, 2026
Special chemicals called surfactants keep the water and diesel evenly blended, allowing the emulsion to remain stable for up to sixty days.
From Science Daily ● Mar. 13, 2026
Flaky hake-fish in a light, briny parsley sauce and an emulsion of olive oil, on a bed of smashed potatoes.
From Salon ● Nov. 8, 2025
He shook a bottle of yellow emulsion labeled Hall’s Cream Salve and poured it into the deep cuts.
From "East of Eden" by John Steinbeck
The study, "Culinary strategies for improving carotenoid bioaccessibility in kale: The role of thermal processing and excipient emulsions," was published in Food Nutrition.
From Science Daily ● Dec. 8, 2025
Personal skincare products, ranging from beauty cosmetics to medical creams, rely on sophisticated "chassis" formulations -- often emulsions or gels -- to effectively deliver active ingredients.
From Science Daily ● Nov. 25, 2024
Depending on the mixture, split emulsions may be recovered by adding more emulsifier and re-whisking or re-mixing.
From Salon ● Jan. 2, 2024
And how can we enhance our emulsions for better salads and more?
From Salon ● Jan. 2, 2024
I go anyway through the ankle- deep water of flooded street corners, the brown pools slicked with spectral emulsions of engine oil and cooking grease, soot and sweat.
From "Native Speaker" by Chang-rae Lee
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
