fantasm
NounWordNet 3.0
Webster's Dictionary (GCIDE)
1.An image formed by the mind, and supposed to be real or material; a shadowy or airy appearance; sometimes, an optical illusion; a phantom; a dream. [1913 Webster]
They be but phantasms or apparitions.— Sir W. Raleigh.[1913 Webster]
2.A mental image or representation of a real object; a fancy; a notion. --Cudworth. [1913 Webster]
Figures or little features, of which the description had produced in you no phantasm or expectation.— Jer. Taylor.[1913 Webster]