protoplasm
Americannoun
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Biology. (no longer in technical use) the colloidal and liquid substance of which cells are formed, excluding horny, chitinous, and other structural material; the cytoplasm and nucleus.
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Obsolete. the living matter of organisms regarded as the physical basis of life, having the ability to sense and conduct stimuli.
noun
Other Word Forms
Etymology
Origin of protoplasm
From the New Latin word prōtoplasma, dating back to 1840–50. See proto-, -plasm
Compare meaning
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Explanation
Protoplasm is the gooey stuff that living cells are made of. A cell's protoplasm is colorless and surrounded by a plasma membrane. Sometimes people use protoplasm to mean “formless blob of life.” There are many elements that make up the protoplasm of a cell, including the nucleus, amino acids, lipids, and ions. Scientists generally use the word protoplasm to mean the cytoplasm plus the nucleus. It was coined in the 1840s by a German scientist, from the Greek roots proto, "first," and plasma, "something molded or formed."
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.
He was the first to have shape-shifting powers, which he gained after encountering a mysterious radioactive pool of protoplasm.
From Los Angeles Times • Apr. 22, 2026
In Darwin’s day scientists could assume that cells contained only a kind of undifferentiated protoplasm.
From The Wall Street Journal • Apr. 16, 2026
From there it wasn’t such a leap to guess that protoplasm might, in certain extraordinary moments, coalesce and be projected from the body.
From Slate • Jul. 18, 2016
Intensities this great can damage individual cells, variously causing their protoplasm to stream inside them, altering their permeability, or rupturing their walls through cavitation.
From Textbooks • Aug. 12, 2015
She probably thinks I'm turning myself into a gob of protoplasm or something.
From "Things Not Seen" by Andrew Clements
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.
