noun met??o??pro??lol \me-??t??-pr??-??lo??l, -??l??l\Definition of METOPROLOL : a beta-blocker C15H25NO3 used in the form of its succinate and tartrate especially to treat hypertension and angina pectoris Origin of METOPROLOLperhaps from methyl + -o- + propranololFirst Known Use: 1974