dicyclic

adjective
  1. botany having the perianth arranged in two whorls; having separate petals and sepals
  2. chem (of a molecule) containing only two rings of atoms
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012