groundless

You would be surprised if you knew the number of complaints made to us, which, on investigation, turn out to be groundless.

But a still more satisfactory answer is, that the apprehension of danger is groundless, and therefore the whole argument fails.

But soon after, a lieutenant of the artillery came in with a groundless report that Green had received reinforcements.

I was, at first, inclined to suspect in my friend some capricious and groundless antipathy.