the world > matter > chemistry > chemical reactions or processes > subject to chemical reactions or processes [verb (transitive)] > subject to process affecting reaction > react (3)
transitive. Chemistry. To give an active property to (a substance) by chemical action. Cf. activate, v. 2a. Now historical and rare.
transitive. Chemistry and Biochemistry. To make (more) reactive; to make capable of chemical, enzymatic, catalytic, etc., action. Also: to initiate…
Chemistry. transitive. To cause (substances, molecules, etc.) to undergo a mutual chemical reaction; to cause to react with (another substance, etc.).