[ pahy-ran, pahy-ran ]
/ ˈpaɪ ræn, paɪˈræn /

noun Chemistry.

either of two compounds having the formula C5H6O, containing one oxygen and five carbon atoms arranged in a six-membered ring.

Origin of pyran

1900–05; pyr(one) + -an, variant of -ane Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for pyran


/ (ˈpaɪræn, paɪˈræn) /


an unsaturated heterocyclic compound having a ring containing five carbon atoms and one oxygen atom and two double bonds. It has two isomers depending on the position of the saturated carbon atom relative to the oxygen

Word Origin for pyran

C20: from pyro- + -an
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

Science definitions for pyran


[ pīrăn′ ]

Any of a class of compounds having a ring of five carbon atoms and one oxygen atom and two double bonds. The pyran ring structure forms part of many organic compounds, especially sugars.
An unstable compound that is the simplest member of this class. Chemical formula: C5H6O.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.