The adjective illusory is a result from an illusion or something that is deceptive, misleading or unreal.

Synonyms are delusional, false, deceitful, or fallacious.

The word origins from the Middle French (1590s) illusorie (modern French illusoire) and Late Latin illusorius meaning “ironical, of a mocking character” from illus-, past participle stem of Latin illudere meaning “mock, jeer at, make fun of” literally meaning “play with”. Its first known use was in circa 1631.

He is a master of illusory speeches.

The prospect of getting their proposal approved is illusory rather than real.

Sometimes, people label horror stories as “based on a true story” but they’re probably just based on illusory experiences.