pyrazolone

[ pi-raz-uh-lohn, pahy- ]

noun

, Chemistry.

1. any of the group of heterocyclic compounds containing the pyrazoline ring in which one carbon atom is doubly linked to an oxygen atom not in the ring.
2. the parent compound, C 3 H 4 N 2 O.

Word History and Origins

Origin of pyrazolone¹

First recorded in 1885–90; pyrazole + -one