big-league (adj.)

"alliance," mid-15c., ligg, from French ligue "confederacy, league" (15c.), from Italian lega, from legare "to tie, to bind," from Latin ligare "to bind" (from PIE root *leig- "to tie, bind"). Originally among nations, subsequently extended to political associations (1846) and sports associations (1879). League of Nations is attested from 1917 (created 1919).