Delusive, a.
Etymology: [See Delude.]
Apt or fitted to delude; tending to mislead the mind; deceptive; beguiling; delusory; as, delusive arts; a delusive dream. Delusive and unsubstantial ideas. Whewell. -- De*lu"sive*ly, adv. -- De*lu"sive*ness, n.
Shades of meaning
Fernald has no entry of its own for delusive; he lists it under vain.
He lists it without comment; the entries above explain its neighbors.