obtuanhydride

Noun

 * 1)  A lichen-derived cyclic acid anhydride diterpene with IUPAC name (7aS,11aS)-2-hydroxy-8,8,11a-trimethyl-3-propan-2-yl-7a,9,10,11-tetrahydrobenzo[d][2]benzoxepine-5,7-dione