ASEabbr. American Stock ExchangeAmerican Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.ASE or A.S.E., American Stock Exchange. -ase a suffix used in the names of enzymes: oxidase. [extracted from diastase] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.