IPA: /ˈoʊvərˌbraɪt/
KK: /oʊvərˈbraɪt/
Excessively bright or shining, often to the point of being uncomfortable or harsh.
The overbright lights in the room made it hard to see clearly.
Comparative: more overbright
Superlative: most overbright
Overbright → It is formed from "over-" (meaning excessively) and "bright" (from Old English "beorht", meaning shining or radiant). The word "overbright" means excessively bright or shining too much.
Think of something that is shining "excessively" ('over-') — that's why overbright means too bright.