The story
- Proto-Indo-European*h₁lengʷʰ-
- Proto-Germanic*linhtaz
- Proto-West Germanic*lį̄ht
- Old Englishlēoht
- Middle Englishlight
- Englishlight
- Englishmind
- Englishminded
- English todaylight-minded
From light (“lacking mental gravity”, adjective) + minded (“having a mind or inclination”, adjective).
Etymology from Wiktionary, CC BY-SA 4.0.