ca ‧ tal ‧ y ‧ sis /kəˈtæləsəs, kəˈtælɪsəs/ BrE AmE noun [uncountable] technical
[ Date: 1600-1700 ; Language: Greek ; Origin: katalysis , from katalyein 'to become liquid' , from kata- ( ⇨ ↑ cataclysm ) + lyein 'to let go, become liquid' ]
the process of making a chemical reaction quicker by adding a catalyst