Imposture, n.
Etymology: [L. impostura: cf. F. imposture. See Impone.]
The act or conduct of an impostor; deception practiced under a false or assumed character; fraud or imposition; cheating. From new legends And fill the world with follies and impostures. Johnson.
Syn. -- Cheat; fraud; trick; imposition; delusion.
Shades of meaning
Fernald has no entry of its own for imposture; he lists it under artifice, fraud.
Where he writes about it:
Imposture is a deceitful contrivance for securing charity, credit, or consideration. — from artifice
An imposture is designed to obtain money, credit, or position to which one is not entitled, and may be practised by a street beggar or by the pretender to a throne. — from fraud