The word "busload" refers to the number of people that a bus can carry. It can be used to indicate a large group of people traveling together on a bus. Full definition
-LCB- 5/19/99 -RCB- It's nine o'clock at night when we get word: A couple of busloads of refugees — the first to cross the border in weeks — will arrive in a half hour. (discovermagazine.com)
During September the entire town, its population swelled by busloads of tourists, celebrates the pepper harvest with a Paprika Festival. (fieryfoodscentral.com)
Nearly a dozen schools have banded together to send busloads of students to the capitol. (knkx.org)