Definition of "groundless" []

• Having no ground or foundation; unsubstantiated: groundless optimism. See Synonyms at baseless. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Chinese officials are warning the United States not to engage in what they call groundless smear attacks against Chinese products."
• "The Tories and the military have suggested the diplomat was duped by the Taliban into writing what they call groundless reports."
• "The claims advanced by Olint, though ultimately would proven to be groundless is very important because it, gave us a brief glimpse into the subtleties of judicial politics."