ace·to·phe·net·i·din \-fəˈned.ədə̇n\noun alsoac·et·phe·net·i·din\|asə̇tfə-\ (-s) Etymology: International Scientific Vocabulary acet- + phenetidin : a white crystalline compound C10H13NO2 used as an analgesic and antipyretic; p-acetophenetidide — called also phenacetin