free radical

noun

Chemistry, Biochemistry.

1. an atom or molecule that bears an unpaired electron and is extremely reactive, capable of engaging in rapid chain reactions that destabilize other molecules and generate many more free radicals: in the body, deactivated by antioxidants, uric acid, and certain enzyme activities.

free radical

noun

1. Sometimes shortened to: radical. an atom or group of atoms containing at least one unpaired electron and existing for a brief period of time before reacting to produce a stable molecule Compare group

free radical

1. An atom or group of atoms that has at least one unpaired electron and is therefore unstable and highly reactive. In animal tissues, free radicals can damage cells and are believed to accelerate the progression of cancer, cardiovascular disease, and age-related diseases.

Word History and Origins

Origin of free radical¹

First recorded in 1895–1900