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n. Chemistry A substance, usually used in small amounts relative to the reactants, that modifies and increases the rate of a reaction without being consumed in the process.

n. One that precipitates a process or event, especially without being involved in or changed by the consequences: "A free press ... has remained ... a vital catalyst to an informed and responsible electorate” ( Robert O'Neal).

n. A substance that increases the rate of a chemical reaction without being consumed in the process.

n. Someone or something that encourages progress or change.

n. A catalytic converter.

n. a substance that initiates or accelerates a chemical reaction without itself being affected.

n. something that serves as a precipitating occasion for an event.

n. something or someone that causes events to happen with itself being changed.

n. In physical chemistry Same as catalytic agent (which see).

n. something that causes an important event to happen

n. (chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected

"Malone had filed the word catalyst in his mental Rolodex, right beside another nagging question."

inhibitor   

cause    causal agency    causal agent   

philatelist   

catalysis    reagents    contaminant    solvent    hydrogenation    dioxide    nitrate    oxide    ion    pesticide