| 1. | Chemistry. noting or pertaining to a chemical change that is accompanied by an absorption of heat (opposed to exothermic ). |
| 2. | Zoology. warm-blooded. |
| 1. | Also, endothermic. designating or pertaining to animals, as mammals and birds, whose blood ranges in temperatures from about 98° to 112°F (37° to 44°C) and remains relatively constant, irrespective of the temperature of the surrounding medium; homoiothermal. |
| 2. | ardent, impetuous, or passionate: young and warm-blooded valor. |

endothermic en·do·ther·mic (ěn'dō-thûr'mĭk) or en·do·ther·mal (-məl)
adj.
Of or relating to a chemical reaction during which there is absorption of heat.
Of or relating to an endotherm; warm-blooded.
warm-blooded adj.
Maintaining a relatively constant and warm body temperature independent of environmental temperature; homeothermic.