\Phan"tasm\, n. [L. phantasma. See {Phantom}, and cf.
{Fantasm}.] [Spelt also {fantasm}.]
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.

         They be but phantasms or apparitions. --Sir W.
                                               Raleigh.

2. A mental image or representation of a real object; a
   fancy; a notion. --Cudworth.

         Figures or little features, of which the description
         had produced in you no phantasm or expectation.
                                               --Jer. Taylor.