/twen'tee fawr"moh, -fohr"-, twun"-/ , n. , pl. twenty-fourmos , adj.
n.
1. a book size of about 3 5 / 8 × 5 1 / 8 in. (9 × 13 cm), determined by printing on sheets folded to form 24 leaves or 48 pages.
2. a book of this size. Symbol: 24mo, 24°
adj.
3. in twenty-fourmo. Also called vigesimoquarto .
[ 1835-45; TWENTY-FOUR + -MO ]