baseless, groundless, idle, unfounded, unwarranted, wild
Meaning: without a basis in reason or fact; "baseless gossip"; "the allegations proved groundless"; "idle fears"; "unfounded suspicions"; "unwarranted jealousy"
I knew him, and you now find that my suspicion was not groundless."
He answered, "Your hopes are groundless. An habitual diarrhoea of more than a year's standing, would be a very bad disease at any age; at my age it is a mortal one.
For his mind was filled not only with the fear that she might escape from him and run away, which he knew was groundless, but with more rational visions, such as wandering curs, traps, gins, spring guns, besides a dread of being seen with her by the neighbourhood.
The gambler, whom I think we should now call the philosopher, received this charge without the least visible emotion either of mind or muscle. After a short pause of a few moments, he answered, with great solemnity, as follows: "Young man, I am entirely unconcerned at your groundless suspicion.
The king's partisans had all along maintained, that the fears and jealousies of the parliament, after the securities so early and easily given to public liberty, were either feigned or groundless; and that no human institution could be better poised and adjusted than was now the government of England.