1. 
[syn: dizzy, giddy, woozy, vertiginous]
The Collaborative International Dictionary of English v.0.48:
Vertiginous \Ver*tig"i*nous\, a. [L. vertiginosus, fr. vertigo a
   whirling around, giddiness: cf. F. vertigineux. See
   Vertigo.]
   1. Turning round; whirling; rotary; revolving; as, a
      vertiginous motion.
      [1913 Webster]
            Some vertiginous whirl of fortune.    --De Quincey.
      [1913 Webster]
   2. Affected with vertigo; giddy; dizzy.
      [1913 Webster]
            They [the angels] grew vertiginous, and fell from
            the battlements of heaven.            --Jer. Taylor.
      [1913 Webster] -- Ver*tig"i*nous*ly, adv. --
      Ver*tig"i*nous*ness, n.
      [1913 Webster]
WordNet (r) 3.0 (2006):
vertiginous
    adj 1: having or causing a whirling sensation; liable to
           falling; "had a dizzy spell"; "a dizzy pinnacle"; "had a
           headache and felt giddy"; "a giddy precipice"; "feeling
           woozy from the blow on his head"; "a vertiginous climb up
           the face of the cliff" [syn: dizzy, giddy, woozy,
           vertiginous]