cocatalyst noun co·cat·a·lyst \ ˌkō-ˈka-tə-ləst \ variants: or co-catalyst Trending Now: More Trending: pansexual symbiote charlatan lowlife kakistocracy SEE ALL See What's Trending Now See More Trending Words What's Trending Now More Trending Words pansexual 'sexual desire or attraction...not limited to a particular gender identity or sexual orientation' symbiote 'an organism living in symbiosis' charlatan 'faker or fraud' lowlife 'a person of low moral character' kakistocracy 'government by the worst people' SEE ALL Time Traveler! Explore the year a word first appeared Definition of cocatalyst plural cocatalysts or co-catalysts : a substance or agent that brings about catalysis in conjunction with one or more others Platina nanoparticles can serve as a co-catalyst in the reactions with electrons … —Science Daily First Known Use of cocatalyst 1961 in the meaning defined above See Words from the same year NEW! Time Traveler Seen and Heard What made you want to look up cocatalyst? Please tell us where you read or heard it (including the quote, if possible). show hide