Past tense of 'giddy': made dizzy or light-headed, or caused to feel excited and frivolous.
From Old English gydig meaning 'possessed by a god' or 'mad.' Over time it shifted to mean dizzy or frivolous, and the verb form developed with the -ed ending.
The original meaning was 'possessed by spirits'—so when you're giddied, you're supposedly made foolish by something outside yourself, which is why excessive sugar makes kids act possessed with energy.
Complete word intelligence in one call. Free tier — 50 lookups/day.