lym·pho·cyte (l?m?f?-s?t?)n. Any of a class of white blood cells of the vertebrate immune system, including the B cells, T cells, and natural killer cells, that in mammals derive from a common progenitor in the bone marrow and are found chiefly in lymph, lymphoid tissues, and blood.lym?pho·cyt?ic (-s?t??k) adj.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.lymphocyte (?l?mf???sa?t) n (Biochemistry) a type of white blood cell formed in lymphoid tissue. See also B-lymphocyte, T-lymphocyte lymphocytic adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014lym?pho?cyte (?l?m f??sa?t) n. a type of white blood cell important in the production of antibodies. Compare B cell (def. 1), T cell. [1885?90] lym`pho?cyt?ic (-?s?t ?k) adj. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.lym·pho·cyte (l?m?f?-s?t?) Any of various white blood cells that function in the body’s immune system by recognizing and deactivating specific foreign substances called antigens. Certain lymphocytes (called B cells) act by stimulating the production of antibodies. Others (T cells) contain receptors on their cell surfaces that are capable of recognizing and binding to specific antigens.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.