Endothermically

Part of speech: adverb

Definitions

1. A process that absorbs heat from the surroundings during a reaction or change in state
2. Describing a chemical reaction that requires the input of thermal energy to proceed to completion
3. Referring to physical changes that take place while extracting heat, leading to a temperature decrease in the immediate environment

Etymology: Endothermically is a technical coinage, not an ancient word. It is simply the adverb form of "endothermic," which is built from the Greek elements "endo-", meaning "within," and "thermos", meaning "hot," with the suffix "-ic" added to make an adjective. The adverb ending "-ally" arrived in English by way of a chain of Latin and Old French forms ending in "-al," followed by Old English "-līċe" and later "-ly," so the final syllables carry a long Germanic and Romance history of their own. Scientists needed a precise term for chemical reactions that take in heat, the opposite of reactions that release it. Describing a reaction as taking place endothermically lets a chemist state, in a single word, that the surroundings lose energy as the reaction proceeds. Dissolving certain salts in water, for example, makes the solution noticeably colder, and chemists describe that process as endothermic.