catˈalyse or (N American) catˈalyze /-līz/ transitive verb

1. To subject to catalysis
2. To act as a catalyst for

catˈalyser or -yzer noun

1. A catalysing agent
2. A catalytic converter

catˈalyst noun

1. A catalysing agent
2. A catalytic converter
3. A person who causes or promotes change by their presence in a situation or their input into it (figurative)

catalytic /-litˈik/ or catalytˈical adjective

catalytˈically adverb

catalytic converter noun

A device fitted to the exhaust of a motor vehicle which converts harmful impurities in the exhaust gases to carbon dioxide, nitrogen and water by oxidation

catalytic cracker see cat-cracker