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

  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, C3H4N2O.

Origin of pyrazolone

First recorded in 1885–90; pyrazole + -one

Words Nearby pyrazolone Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023