metabolism

noun

me·​tab·​o·​lism mə-ˈta-bə-ˌli-zəm 

1

a

: the sum of the processes in the buildup and destruction of protoplasm

specifically : the chemical changes in living cells by which energy is provided for vital processes and activities and new material is assimilated (see assimilate entry 1 sense 1b)

Regular exercise can help to increase your metabolism.

b

: the sum of the processes by which a particular substance is handled in the living body

c

: the sum of the metabolic activities taking place in a particular environment

the metabolism of a lake

2

: metamorphosis sense 2

—usually used in combination

holometabolism

Examples of metabolism in a Sentence

studying the metabolisms of various organisms

Recent Examples on the Web

Researchers believe prunes work through anti-inflammatory compounds, polyphenols and their effect on gut health and calcium metabolism, though the full mechanism is still being studied. —Allison Palmer updated June 3, Charlotte Observer, 3 June 2026

Researchers believe prunes’ mix of polyphenols, anti-inflammatory compounds and effect on gut health and calcium metabolism are behind the results, though the exact mechanism is still being studied. —Allison Palmer updated June 3, Sacbee.com, 3 June 2026

Some studies suggest that non-nutritive sweeteners can change your metabolism, affecting your insulin sensitivity and blood sugar control. —Cristina Mutchler, Verywell Health, 3 June 2026

One is sold to people, and the other is wired into the metabolism of a business. —Ashutosh Saxena, Forbes.com, 1 June 2026

Word History

Etymology

metabol(ic) + -ism, after French métabolisme or German Metabolismus

First Known Use

1878, in the meaning defined at sense 1a

Phrases Containing metabolism

• basal metabolism

Rhymes for metabolism

• activism
• albinism
• altruism
• aneurism
• animism
• aphorism
• atomism
• barbarism
• bolshevism
• botulism
• brahmanism
• calvinism

Kids Definition

metabolism

noun

me·​tab·​o·​lism mə-ˈtab-ə-ˌliz-əm 

1

: the processes essential for life by which the complex substances in the cells of living things are built up or broken down

2

: the processes by which a particular substance (as iodine) is handled in the living body

Medical Definition

metabolism

noun

me·​tab·​o·​lism mə-ˈtab-ə-ˌliz-əm 

1

a

: the sum of the processes in the buildup and destruction of protoplasm

specifically : the chemical changes in living cells by which energy is provided for vital processes and activities and new material is assimilated

methods of determining body and tissue metabolism

—Bulletin of the University of Kentucky

see anabolism, catabolism

b

: the sum of the processes by which a particular substance is handled (as by assimilation and incorporation or by detoxification and excretion) in the living body

the metabolism of iodine in the thyroid

2

: metamorphosis sense 2

—usually used in combination

holometabolism