blood plasman. The pale yellow or gray-yellow, protein-containing fluid portion of the blood in which the blood cells and platelets are normally suspended.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.blood plasma n 1. (Physiology) the pale yellow fluid portion of the blood; blood from which red and white blood cells and platelets have been removed 2. (Physiology) a sterilized preparation of this fluid for use in transfusions Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014blood? plas`ma n. the liquid portion of vertebrate blood. [1905?10] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.blood plasma The clear, liquid part of the blood, composed mainly of water and proteins, in which the blood cells are suspended. The blood plasma of mammals also contains platelets.The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.