[ proh-tuh-plast ]
/ ˈproʊ təˌplæst /


  1. the contents of a cell within the cell membrane, considered as a fundamental entity.
  2. the primordial living unit or cell.
a person or thing that is formed first; original; prototype.
the hypothetical first individual or one of the supposed first pair of a species or the like.

Origin of protoplast

1525–35; < Late Latin prōtoplastus the first man, noun use of Greek prōtóplastos formed first. See proto-, -plast

Related forms

pro·to·plas·tic, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for protoplast

British Dictionary definitions for protoplast


/ (ˈprəʊtəˌplæst) /


a unit consisting of the living parts of a cell, including the protoplasm and cell membrane but not the vacuoles or (in plants) the cell wall

Derived Forms

protoplastic, adjective

Word Origin for protoplast

C16: from Late Latin prōtoplastus the first-formed, from Greek prōtoplastos, from proto- + plassein to shape
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for protoplast


[ prōtə-plăst′ ]


The living material of a plant or bacterial cell, including the protoplasm and plasma membrane after the cell wall has been removed.
One that is the first made or formed; a prototype.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.