Synonyms:
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"
Usage examples
No, quite the contrary; I see that society takes up a sort of antagonistic attitude to these people, which is utterly baseless, and I fancy there's envy at the bottom of it...."
Suppose, after all, I am not the victim of atmospheric refraction, and they are, indeed, as gallant and bold and intelligent as my baseless conception of them would have them be!