Definition of impostor noun in Oxford Advanced Learner's Dictionary. Meaning , pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. Impostor definition : a person who practices deception under an assumed character, identity, or name.. See examples of IMPOSTOR used in a sentence. The meaning of IMPOSTOR is one that assumes false identity or title for the purpose of deception. How to use impostor in a sentence. History and Origin The word “ imposter ” comes from the Latin imponere, meaning “to place upon” or “to deceive.” It entered English in the early 16th century, initially referring to someone who deceives by assuming a false identity. The term was closely associated with fraudulence and trickery, particularly in social or professional contexts. Over time, it expanded in use to describe anyone who presents themselves dishonestly, whether in a formal setting or casual encounter.
