The noun “allusion” means “an indirect reference; a casual mention.”
The noun “illusion” means “a false idea or perception that is not consistent with facts; an unreal or misleading appearance.”
Throughout the evening, my date made allusions to his fancy car, his expensive house, and his lucrative job. He was probably under the illusion that I would be impressed by his wealth.
The magician made an allusion to Houdini by trying to duplicate one of his stunts. Most magic tricks are simply clever illusions.
The novice writer made a literary allusion to a famous author in an attempt to create the illusion that he was sophisticated and well read. In fact, he had never owned any of the author’s books and had read only excerpts and reviews.
Read Grammar Examples of the use of these words: 1
