twenty-fourmo

noun

twen·​ty-four·​mo ˌtwen-tē-ˈfȯr-(ˌ)mō 

ˌtwən-

plural twenty-fourmos

: the size of a piece of paper cut 24 from a sheet

also : a book, a page, or paper of this size

Word History

First Known Use

circa 1841, in the meaning defined above