Definition of "unicellular" []

• Having or consisting of one cell; one-celled: unicellular organisms. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "So Mike has been cataloging a number of components that have one use in unicellular life, and a different use in multicellular life, to show that front loaded designs wouldn't necessarily be lost in the future."
• "Cytosine deamination, controlled variation and the immunological functions are nicely linked and analogous systems in unicellular organisms can be found."
• "For example purposeful behavior surely occurred in unicellular eukaryotic ancestors of modern organisms like paramecia and euglena who perform rather complex adaptive movements."