giddiness          
noun [ U ] uk/ˈɡɪd.i.nəs/ us/ˈɡɪd.i.nəs/
 飘飘然的感觉
a silly, happy, excited feeling that shows in your behaviour
  His childlike excitement verged on giddiness. 他孩子般的兴奋让他飘飘然的。 
  眩晕,头晕目眩
a temporary feeling that your sense of balance is not good and that you may fall down
  Inhalation of the gas can cause headache or giddiness. 吸入这种气体会导致头痛和眩晕。 
 Synonym: dizziness (FEELING)