From big brain +‎ -ed.

big-brained (comparative more big-brained, superlative most big-brained)

1. intellegent; clever
   • 2025 January 3, Christina Izzo, “Cunk On Life is brilliantly funny (and depressingly timely)”, in AV Club‎^[1]:

     Morgan remains a god-tier troll throughout the wide-ranging “documentary,” as Cunk sits opposite Nobel Laureates, neuroscientists, theologian scholars, and other big-brained folks to discuss creationism, evolution, nihilism, and the roots of human existence.