Also found in: Encyclopedia, Wikipedia.
Any of several minute calcite plates that make up the external covering of certain haptophyte phytoplankton and in a fossilized state form chalk and limestone deposits.
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.
(Geological Science) any of the round calcareous plates in chalk formations: formed the outer layer of unicellular plankton
[C19: New Latin, from Greek kokkos berry + lithos stone]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
a microscopic calcareous disk or ring making up part of the covering of certain marine plankton and forming much of the content of chalk rocks.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.