Metabolism
Etymology
From Greek "metabole," meaning change or transformation, from "metaballein" (to change), combining "meta-" (over, across) and "ballein" (to throw). The word names the constant throwing-over of one molecule into another that keeps a body alive.
noun · /muh-TAB-uh-liz-um/
The whole set of chemical reactions cells use to turn food into energy and building material and to clear waste.
What it names
A handle for the body’s ongoing internal chemistry — the running engine, not any single meal.
Example
Cold weather nudges your metabolism to burn more just to hold body temperature.
Related idea
Digestion is only the front end — breaking food into absorbable pieces in the gut — while metabolism is everything cells then do with those pieces, including building tissue and generating heat. Digestion feeds metabolism; it is not the same process.