catalyst B2 Topic:Science & Research US /ˈkæt.ə.lɪst/ UK /ˈkæt.ɪ.lɪst/ See IPA manual Freq #21475 Meanings 1 noun Something or someone that causes an important change or event to happen. The protest was the catalyst for major political reform. 2 noun A substance that speeds up a chemical reaction without being used up itself. Enzymes act as catalysts in the body's chemical reactions. Thesaurus Synonyms 1 noun · something or someone that... stimulus 2 noun · a substance that speeds up... accelerator Word family Forms catalysts Derived forms catalysecatalysiscatalyticcatalyze Related forms enzyme Etymology AI details From catalysis + -ist. Topics Science & Research Materials & Substances External links Cambridge Dictionary Wiktionary Google Images # catalyst **Type:** Word **Level:** B2 **Part of speech:** noun **IPA (US):** /ˈkæt.ə.lɪst/ **IPA (UK):** /ˈkæt.ɪ.lɪst/ **Frequency rank:** 21475 ## Meanings 1. Something or someone that causes an important change or event to happen. 2. A substance that speeds up a chemical reaction without being used up itself. ## Examples - The protest was the catalyst for major political reform. - Enzymes act as catalysts in the body's chemical reactions. ## Derived Forms - catalyse - catalysis - catalytic - catalyze ## Related Forms - enzyme ## Etymology From catalysis + -ist. ## AI Etymology catalyst is a noun. It is from catalysis + -ist. Current senses include something or someone that causes an important change or event to happen and a substance that speeds up a chemical reaction without being used up itself. Derived forms include catalyse, catalysis, catalytic, and catalyze. Related words include enzyme. ## Topics - Science & Research - Materials & Substances markdown