adj.
 relating to the eye or vision.
n.
   - a lens or other optical component in an optical instrument.
 - archaic or humorous the eye.
 - Brit. trademark a device fastened to the neck of an inverted bottle for measuring out spirits.
 
 
  Etymology
  ME: from Fr. optique or med. L. opticus, from Gk optikos, from optos ‘seen’.