The story
Shortening of the IUPAC name 1,2-dihydro-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one, taking the first syllable phen of phenyl, az from pyrazole, and -one.
Etymology from Wiktionary, CC BY-SA 4.0.
phenazone
Today it means: A particular analgesic. Full definition →