pyrazoline

[ pi-raz-uh-leen, -lin, pahy- ]
/ pɪˈræz əˌlin, -lɪn, paɪ- /

noun Chemistry.

any of the group of heterocyclic compounds containing three carbon atoms, two adjacent nitrogen atoms, and one double bond in the ring.
the parent compound, C3H6N2.

Origin of pyrazoline

First recorded in 1885–90; pyrazole + -ine2