The story
- Proto-West Germanic · inherited from*berhtnassī
- Old English · inherited frombeorhtnes“brightness, splendor”
- Middle English · inherited frombryghtnes
- English todaybrightness
From Middle English bryghtnes, brightnesse, from Old English beorhtnes (“brightness, splendor”), from Proto-West Germanic *berhtnassī, equivalent to bright + -ness. Cognate with Old High German berahtnessī, berahtnessi (“brightness”).
Etymology from Wiktionary, CC BY-SA 4.0.