imposter

UK: /ɪmˈpɒstəʳ/

WordReference Random House Learner's Dictionary of American English © 2026

im•pos•tor or im•post•er /ɪmˈpɑstɚ/   n. [countable]

1. one who pretends to be another in order to deceive someone:
   One of these is an impostor; can you figure out which?

See -pos-.

WordReference Random House Unabridged Dictionary of American English © 2026

im•post¹  (im′pōst), n. 

1. a tax;
   tribute;
   duty.
2. a customs duty.
3. Sport [Horse Racing.] the weight assigned to a horse in a race.

v.t. 

4. to determine customs duties on, according to the kind of imports.

• Medieval Latin impostus a tax, noun, nominal use of Latin impostus, variant of impositus imposed; see imposition
• 1560–70

im′post•er, n. 

im•post²  (im′pōst), n. [Archit.]

1. Architecture the point of springing of an arch;
   spring.
2. Architecture an architectural feature immediately beneath this point.

• Latin: feminine of impostus (past participle); see impost¹
• Italian imposta
• French imposte
• 1655–65

WordReference Random House Unabridged Dictionary of American English © 2026

im•pos•tor  (im pos′tər), n. 

1. a person who practices deception under an assumed character, identity, or name.

Also, im•post′er. 

• Late Latin, equivalent. to Latin impos(i)-, variant stem of impōnere to deceive, place on (see impone) + -tor -tor
• 1580–90

Collins Concise English Dictionary © HarperCollins Publishers::

impostor, imposter / ɪmˈpɒstə/ noun

1. a person who deceives others, esp by assuming a false identity; charlatan

Etymology: 16th Century: from Late Latin: deceiver; see impose