activation

n. turning on, making active, setting in motion

This article describes the natural science term. For "activation" as it refers to computer software, see product activation. Activation in science generally refers to the process whereby something is prepared or excited for a subsequent reaction.
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Noun
1. stimulation of activity in an organism or chemical
(antonym) inactivation
(hypernym) stimulation
(hyponym) indweller
(derivation) activate
2. the activity of causing to have energy and be active
(synonym) energizing, activating
(hypernym) activity
(hyponym) electrification
3. making active and effective (as a bomb)
(antonym) deactivation, defusing
(hypernym) beginning, start, commencement
(derivation) activate

n. activation, making active

The process of making a radioisotope by bombarding a stable element with neutrons or protons.