(transitive) To encourage development or induce increased activity; to stimulate.

(transitive) To put a device, mechanism (alarm etc.) or system into action or motion; to trigger, to actuate, to set off, to enable.

(transitive, chemistry, physics) To render more reactive; excite.

(transitive, biology) To render a molecule reactive, active, or effective in performing its function.

(transitive, physics) To render a substance radioactive.

(transitive, chemistry) To hasten a chemical reaction, especially by heating.

(transitive, computing, software) To remove the limitations of demoware by providing a license; to unlock.

(transitive) To aerate in order to aid decomposition of organic matter.

(transitive, military) To organize or create a military unit or station.

(transitive, sports) To bring a player back after an injury.