[ lahy-eys, -eyz ]
/ ˈlaɪ eɪs, -eɪz /

noun Biochemistry.

any of various enzymes, as decarboxylase, that catalyze reactions involving the formation of or addition to a double bond.

Origin of lyase

1960–65; < Greek lý(ein) to loosen, dissolve (see lysis) + -ase Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for lyase

/ (ˈlaɪeɪz) /


any enzyme that catalyses the separation of two parts of a molecule by the formation of a double bond between them

Word Origin for lyase

C20: from Greek lusis a loosening + -ase
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

Medical definitions for lyase

[ līās′ ]


Any of a group of enzymes that catalyze the formation of double bonds by removing chemical groups from a substrate without hydrolysis or catalyze the addition of chemical groups to double bonds.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.