D defs.my
Entry 1 sense Webster, 1913

Perchloric

/pẽrk-lôr'-ĭk/ · Per·chlo·ric · IPA /pərklˈɔrɪk/
01 a. Pertaining to, or designating, the highest oxygen acid (HClO4), of chlorine; -- called also hyperchloric.
  1. 1.
    Pertaining to, or designating, the highest oxygen acid (HClO4), of chlorine; -- called also hyperchloric.(Chem.) Also: hyperchloric