Illustrated Glossary of Organic Chemistry

Tricyclic: A cyclic molecule containing three rings.



Anthracene is a tricyclic molecule
with three fused benzene rings.		   
  Dicyclopentadiene is bridged tricyclic molecule. Its
IUPAC name is tricyclo[5.2.1.02,6]deca-3,8-diene		   
This tricyclic spiro molecule contains one
cyclopropane ring and two cyclobutane rings.