from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Faint, giddy, or delirious: lightheaded with wine.
- adj. Given to frivolity; silly.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Dizzy or feeling faint, usually caused by a drop in blood pressure to the brain.
light + headed (Wiktionary)