[il.lu.sion] n [ME, fr. MF, fr. LL illusion-, illusio, fr. L, action of mocking, fr. illudere to mock at, fr. in- + ludere to play, mock--more at ludicrous] (14c) 1 a obs: the action of deceiving b (1): the state or fact of being intellectually deceived or misled: misapprehension (2): an instance of such deception
2. a (1): a misleading image presented to the vision (2): something that deceives or misleads intellectually b (1): perception of something objectively existing in such a way as to cause misinterpretation of its actual nature (2): hallucination 1 (3): a pattern capable of reversible perspective
3: a fine plain transparent bobbinet or tulle usu. made of silk and used for veils, trimmings, and dresses -- il.lu.sion.al adj