[1] : The Collaborative International Dictionary of English v.0.48

spy \spy\, n.; pl. spies spimacz. see spy, v., and cf.
   espy, n.
   1. one who keeps a constant watch of the conduct of others.
      "these wretched spies of wit." --dryden.
      1913 webster

   2. mil. a person sent secretly into an enemy's camp,
      territory, or fortifications, to inspect his works,
      ascertain his strength, movements, or designs, and to
      communicate such intelligence to the proper officer.
      1913 webster

   spy money, money paid to a spy; the reward for private or
      secret intelligence regarding the enemy.

   spy wednesday eccl., the wednesday immediately preceding
      the festival of easter; -- so called in allusion to the
      betrayal of christ by judas iscariot.
      1913 webster

   syn: see emissary, and scout.
        1913 webster
see also:
spies spy espy spy money spy wednesday emissary 
scout 

Wednesday >> W Words
Wednesday, definition of term: Wednesday
wednesday_pag1.html

Spy >> S Words
Spy, definition of term: Spy
spy_pag1.html

Ash Wednesday >> A Words
Ash Wednesday, definition of term: Ash Wednesday
ash+wednesday_pag1.html