/məˈtabəˌlizəm/
Noun
1. The complete set of chemical reactions that occur in living cells. (wiktionary.org)
2. The chemical processes that occur within a living organism in order to maintain life. (Google Dictionary)
3. The organic processes (in a cell or organism) that are necessary for life. (wordnetweb.princeton.edu)
4. The sum of all the physical and chemical processes by which living organized substance is produced and maintained (anabolism), and also the transformation by which energy is made available for the uses of the organism (catabolism). (Dorland’s Medical Dictionary for Health Consumers)
5. The process involving a set of chemical reactions that modifies a molecule into another for storage, or for immediate use in another reaction or as a by product. (biology-online.org)
Word origin: From French métabolisme, from Greek metabole “a change,” from metaballein “to change,” from meta- “over” + ballein “to throw.”