well-read

civilized, cultivated, cultured

cerebral, highbrow, highbrowed, intellectual

polished, refined, well-bred

academic (also academical), bookish, didactic, didactical, inkhorn, pedantic, professorial

informed, instructed, schooled, skilled, trained

homeschooled, self-educated, self-instructed, self-taught

briefed, enlightened, informed, versed