1. adin a bright manner. luminous; shiny; radiant; cheerful; intelligent, clever; clear. intelligent, brainy, sharp I left the water running. That wasn't a very bright thing to do. brightbright , v. i. see: brite, v. i.bright bright , a. [oe. briht, as. beorht, briht; akin to os. berht, ohg. beraht, icel. bjartr, goth. ba?rhts. ?94.]