sesquicentennial[-sen ten′ē əl, -ten′yəl]
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
of or ending a period of 150 years
a 150th anniversary or its commemoration
Used by arrangement with John Wiley & Sons, Inc.
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Of or relating to a period of 150 years.noun
A 150th anniversary or its celebration.