From Old English 'beorht' and PIE *bherg- (to shine) — the same root hiding inside the names Albert and Robert.
Giving out or reflecting much light; shining; intelligent and quick-witted; vivid in color.
From Old English 'beorht' (bright, shining, splendid, magnificent), from Proto-Germanic *berhtaz, meaning 'bright, shining.' The PIE root is *bʰerǵ- meaning 'to shine, to be white or bright.' The same root produced Gothic 'bairhts' (bright, manifest), Old Norse
The '-bert' in names like Albert, Robert, Herbert, and Hubert comes from the same Germanic root as 'bright' — Old High German 'beraht' (bright, famous). Albert means 'noble-bright,' Robert means 'fame-bright,' and Bertha means simply 'the bright one.' Every person named Bert is etymologically radiant.