lə̇ˈpōik- noun
Etymology: lip- + -ic
: any of several microbial growth factors occurring especially in yeast and liver ; specifically : the crystalline alpha variety C 7 H 13 S 2 COOH that together with cocarboxylase and other factors is essential for the oxidation of alpha-keto acids (as pyruvic acid to acetic acid) during metabolic changes in the body; 6,8-epi-dithio-octanoic acid — compare thioctic acid