Source : Webster's Revised Unabridged Dictionary (1913)

Vertiginous \Ver*tig"i*nous\, a. [L. vertiginosus, fr. vertigo a
   whirling around, giddiness: cf. F. vertigineux. See
   {Vertig??}.]
   1. Turning round; whirling; rotary; revolving; as,
      vertiginous motion.

            Some vertiginous whirl of fortune.    --De Quincey.

   2. Affected with vertigo; giddy; dizzy.

            They [the angels] grew vertiginous, and fell from
            the battlements of heaven.            --Jer. Taylor.
      -- {Ver*tig"i*nous*ly}, adv. -- {Ver*tig"i*nous*ness}, n.

Source : WordNet®

vertiginous
     adj : 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}]