Giddy

duizelig

(feeling a sense of spinning in the head, causing a perception of unsteadiness and being about to fall down — see also dizzy)

duizelingwekkend

(causing or likely to cause dizziness or a feeling of unsteadiness)

lichtzinnig

(unable to concentrate or think seriously; easily excited — see also impulsive)

onbezonnen

(lightheartedly silly — see also frivolous)