'Impostor' definitions:

Definition of 'impostor'

From: WordNet
noun
A person who makes deceitful pretenses [syn: imposter, impostor, pretender, fake, faker, fraud, sham, shammer, pseudo, pseud, role player]

Definition of 'Impostor'

From: GCIDE
  • Impostor \Im*pos"tor\, n. [L. impostor a deceiver, fr. imponere to impose upon, deceive. See Impone.] One who imposes upon others; a person who assumes a character or title not his own, for the purpose of deception; a pretender. "The fraudulent impostor foul." --Milton.
  • Syn: Deceiver; cheat; rogue. See Deceiver. [1913 Webster]