资料来源 : Webster's Revised Unabridged Dictionary (1913)

Spy \Spy\, v. t. [imp. & p. p. {Spied}; p. pr. & vb. n.
   {Spying}.] [OE. spien, espien, OF. espier, F. ['e]pier, OHG.
   speh?n, G. sp["a]hen; akin to L. specere to see, Skr. spa(?).
   ? 169. Cf. {Espy}, v.t., {Aspect}, {Auspice}, {Circumspect},
   {Conspicuouc}, {Despise}, {Frontispiece}, {Inspect},
   {Prospect}, {Respite}, {Scope}, {Scecimen}, {Spectacle},
   {Specter}, {Speculate}, {Spice}, {Spite}, {Suspicion}.]
   To gain sight of; to discover at a distance, or in a state of
   concealment; to espy; to see.

         One in reading, skipped over all sentences where he
         spied a note of admiration.              --Swift.

   2. To discover by close search or examination.

            Look about with yout eyes; spy what things are to be
            reformed in the church of England.    --Latimer.

   3. To explore; to view; inspect; and examine secretly, as a
      country; -- usually with out.

            Moses sent to spy Jaazer, and they took the villages
            thereof.                              --Num. xxi.
                                                  32.

资料来源 : WordNet®

spying
     n 1: keeping a secret or furtive watch
     2: the act of keeping a secret watch for intelligence purposes
        [syn: {undercover work}]
     3: the act of detecting something; catching sight of something
        [syn: {detection}, {catching}, {espial}, {spotting}]