overarch definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
transitive verb, intransitive verb
to form an arch over (something)
overarch definition by American Heritage Dictionary
transitive verb o·ver·arched, o·ver·arch·ing, o·ver·arch·es
To form an arch over: Grape vines overarched the garden path.