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A cell of a plant, fungus, bacterium, or archaeon from which the cell wall has been removed, leaving the protoplasm and plasma membrane.
[French protoplaste, from Old French, the first man, from Late Latin prōtoplastus, from Greek prōtoplastos : prōto-, proto- + plastos, formed, molded; see -plast.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.