|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
|a gadget; dingus; thingumbob.|
perchloric acid per·chlo·ric acid (pər-klôr'ĭk)
A clear colorless liquid that is the highest in oxygen content of the series of chlorine acids and is a powerful oxidant used as a catalyst.
|perchloric acid (pər-klôr'ĭk) Pronunciation Key
A clear, colorless liquid that is very corrosive and, under some conditions, extremely explosive. It is a powerful oxidant and is used as a catalyst and in explosives. Chemical formula: HClO4.