warm-blood·ed also warm·blood·ed (wôrm?bl?d??d)adj.1. Zoology Maintaining a relatively constant and warm body temperature independent of environmental temperature; homeothermic.2. Ardent; passionate.warm?-blood?ed·ness, warm?blood?ed·ness n.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.warm-blooded adj 1. ardent, impetuous, or passionate 2. (Zoology) (of birds and mammals) having a constant body temperature, usually higher than the temperature of the surroundings. Technical name: homoiothermic ?warm-?bloodedness nCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014warm?-blood?ed or warm?blood?ed, adj. 1. of or designating animals, as mammals and birds, having a body temperature that is relatively constant and independent of the environment. 2. ardent; impetuous: warm-blooded valor. [1785?95] warm?-blood?ed?ness, n. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.warm-blood·ed (wôrm?bl?d??d) Having a relatively warm body temperature that stays about the same regardless of changes in the temperature of the surroundings. Birds and mammals are warm-blooded.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.