The Collaborative International Dictionary of English v.0.48:

Swoon \Swoon\, n.
   A fainting fit; syncope.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Swoon \Swoon\, v. i. [imp. & p. p. Swooned; p. pr. & vb. n.
   Swooning.] [OE. swounen, swoghenen, for swo?nien, fr.
   swo?en to sigh deeply, to droop, AS. sw[=o]gan to sough,
   sigh; cf. gesw[=o]gen senseless, swooned, gesw[=o]wung a
   swooning. Cf. Sough.]
   To sink into a fainting fit, in which there is an apparent
   suspension of the vital functions and mental powers; to
   faint; -- often with away.
   [1913 Webster]

         The sucklings swoon in the streets of the city. --Lam.
                                                  ii. 11.
   [1913 Webster]

         The most in years . . . swooned first away for pain.
                                                  --Dryden.
   [1913 Webster]

         He seemed ready to swoon away in the surprise of joy.
                                                  --Tatler.
   [1913 Webster]

WordNet (r) 3.0 (2006):

swoon
    n 1: a spontaneous loss of consciousness caused by insufficient
         blood to the brain [syn: faint, swoon, syncope,
         deliquium]
    v 1: pass out from weakness, physical or emotional distress due
         to a loss of blood supply to the brain [syn: faint,
         conk, swoon, pass out]