forty-eightmo

forty-eightmo [fawr-tee-eyt-moh] Word Origin noun, plural for·ty-eight·mos for 2.

1. a book size of about 2½ × 4 inches (6 × 10 cm), determined by printing on sheets folded to form 48 leaves or 96 pages. Abbreviation: 48mo, 48°
2. a book of this size.

adjective

3. in forty-eightmo.

Origin of forty-eightmo First recorded in 1885–90; forty-eight + -mo