[ pol-ee-sahy-klik, -sik-lik ]
/ ˌpɒl iˈsaɪ klɪk, -ˈsɪk lɪk /

adjective Chemistry.

pertaining to an organic compound containing several atomic rings, usually fused.

Origin of polycyclic

First recorded in 1865–70; poly- + cyclic
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Examples from the Web for polycyclic

  • Pierced Roger's polycyclic screen; exposed the bare metal of Roger's walls!

    Triplanetary|Edward Elmer Smith
  • That must be that polycyclic screen that Conway reported on.

    Triplanetary|Edward Elmer Smith

British Dictionary definitions for polycyclic

/ (ˌpɒlɪˈsaɪklɪk) /


(of a molecule or compound) containing or having molecules that contain two or more closed rings of atoms
biology having two or more rings or whorlspolycyclic shells; a polycyclic stele


a polycyclic compoundanthracene is a polycyclic
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

Scientific definitions for polycyclic

[ pŏl′ĭ-sīklĭk, -sĭklĭk ]

Having two or more atomic rings in a molecule. Steroids are polycyclic compounds.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.