Entry 1 sense Webster, 1913 Oxybutyric · Ox·y·bu·tyr·ic · IPA 01 a. Hydroxybutyric; designating any one of a group of metameric acids ((C3H6.OH).CO2H). 1. Hydroxybutyric; designating any one of a group of metameric acids ((C3H6.OH).CO2H).(Chem.)