UNFOUNDED

baseless, groundless, idle, unfounded, unwarranted, wild

(adjective) without a basis in reason or fact; “baseless gossip”; “the allegations proved groundless”; “idle fears”; “unfounded suspicions”; “unwarranted jealousy”

Source: WordNet® 3.1

Etymology

Adjective

unfounded (not comparable)

Having no strong foundation; not based on solid reasons or facts.

Synonyms: baseless, groundless, ungrounded

Not having been founded or instituted.

(obsolete) Bottomless.

Source: Wiktionary

Un*found"ed, a.

1. Not founded; not built or established. Milton.

2. Having no foundation; baseless; vain; idle; as, unfounded expectations. Paley.

Source: Webster’s Unabridged Dictionary 1913 Edition