(ˈ)prā|nid.ik-, (ˈ)pre|- noun
Etymology: International Scientific Vocabulary prehnite + -ic; probably from the resemblance of the crystals to the mammillae on prehnite
: either of two isomeric acids derived from benzene:
a. : mellophanic acid b
b. : a crystalline acid C 6 H 2 (COOH) 4 formed especially by oxidation of prehnitene; 1,2,3,4-benzene-tetracarboxylic acid