C-re·ac·tive protein (s??r?-?k?t?v)n. A globulin that appears in the blood in certain acute inflammatory conditions, such as rheumatic fever, bacterial infections, and neoplastic diseases.[C-(polysaccharide) reactive.]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.C-re?ac?tive protein (?si ri?æk t?v) n. a globulin that increases in concentration in the bloodstream during infectious states and other abnormal conditions. Abbr.: CRP [1955?60; for C-polysaccharide, which is precipitated by this protein] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.