Lewis & Short

† phantăsĭa, ae, f., = φαντασία,

  1. I. an idea, notion, fancy (post-Aug.): Nicetas longe disertius hanc phantasiam movit, Sen. Suas. 2, 15: cor tuum phantasias patitur, Vulg. Ecclus. 34, 6.
    As a term of reproach: phantasia, non homo, a mere notion or fancy, the mere semblance of a man, Petr. 38 fin. (in Cic. Ac. 1, 11, 40; 2, 6, 8 al., written as Greek, and translated visum).
  2. II. A phantom, apparition: (animus) colli-git visa nocturna, quas phantasias nos adpellamus, Amm. 14, 11, 18.