The Collaborative International Dictionary of English v.0.48:

Snare \Snare\, n. [AS. sneara cord, a string; akin to D. snoer,
   G. schnur, OHG. snour a cord, snarahha a noose, Dan. snare,
   Sw. & Icel. snara, Goth. sn?rj? a basket; and probably also
   to E. needle. See Needle, and cf. Snarl to entangle.]
   1. A contrivance, often consisting of a noose of cord, or the
      like, by which a bird or other animal may be entangled and
      caught; a trap; a gin.
      [1913 Webster]

   2. Hence, anything by which one is entangled and brought into
      trouble.
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            If thou retire, the Dauphin, well appointed,
            Stands with the snares of war to tangle thee.
                                                  --Shak.
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   3. The gut or string stretched across the lower head of a
      drum.
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   4. (Med.) An instrument, consisting usually of a wireloop or
      noose, for removing tumors, etc., by avulsion.
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   Snare drum, the smaller common military drum, as
      distinguished from the bass drum; -- so called because (in
      order to render it more resonant) it has stretched across
      its lower head a catgut string or strings.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Snare \Snare\, v. t. [imp. & p. p. Snared; p. pr. & vb. n.
   Snaring.]
   To catch with a snare; to insnare; to entangle; hence, to
   bring into unexpected evil, perplexity, or danger.
   [1913 Webster]

         Lest that too heavenly form . . . snare them. --Milton.
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         The mournful crocodile
         With sorrow snares relenting passengers. --Shak.
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WordNet (r) 3.0 (2006):

snare
    n 1: something (often something deceptively attractive) that
         catches you unawares; "the exam was full of trap
         questions"; "it was all a snare and delusion" [syn: trap,
         snare]
    2: a small drum with two heads and a snare stretched across the
       lower head [syn: snare drum, snare, side drum]
    3: a surgical instrument consisting of wire hoop that can be
       drawn tight around the base of polyps or small tumors to
       sever them; used especially in body cavities
    4: strings stretched across the lower head of a snare drum; they
       make a rattling sound when the drum is hit
    5: a trap for birds or small mammals; often has a slip noose
       [syn: snare, gin, noose]
    v 1: catch in or as if in a trap; "The men trap foxes" [syn:
         trap, entrap, snare, ensnare, trammel]
    2: entice and trap; "The car salesman had snared three potential
       customers" [syn: hook, snare]