vertiginous (
http://definr.com/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]