illusions Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. a false or misleading idea or fantasy; a state of seeing hearing or otherwise sensing things in a false way Example Sentence The boy saw optical illusions in the book. Synonyms delusion; fantasy; false appearance; false belief Antonyms certainty; fact; reality; truth Hear It! Say It! Write It! illusions Switch to cursive Start Share with your friends: