catalyst What is the Definition of catalyst?Noun:(chemistry)something that causes an important event to happen Other meanings of catalyst (synonyms, cognates). ENRU catalyst катализатор Frequently viewed: vast meaningtalent meaninghash definitionstore meaningdefinition of writdefinition of collectpretend meaningdefinition of warmpersonal meaningparticipate in a sentencedefinition of continuouscolumn definition A B C D E F G H I J K L M N O P Q R S T U V W X Y Z