1)to be completely enamored with someone/something.
2) the flighty exciting feeling you get when you think about/see the object of your affection.
3) romantically excited (i.e.: aroused)
4) the ever increasing acceleration of heartbeat and body temperature as a result of being engulfed amidst the exhilaration and joy of being/having a romantic entity in someone's life.
When he smiled at her, the rush of warm, fuzzy, excited sensations that filled her made her realize she was completely twitterpated with this man.