The phrase "big billboard" refers to a large outdoor advertising sign usually located along roads or highways. It is used to display advertisements or messages that can be seen by many people passing by. Full definition
I loved modeling and felt that it was my dream job at the time — to shoot big campaigns and make it onto big billboards in LA. (stylelullaby.com)
Cold calling, organizing client parties, buying big billboard ads — these traditional activities can be time - consuming, expensive, and downright unpleasant. (realtormag.realtor.org)