Dictionary
twen•ty•mo
Pronunciation: (twen'tē-mō", twun'-), [key]
—n., pl. -mos,
—adj.
—
n.
1. a book size of about 3 × 5 in. (8 × 12 cm), determined by printing on sheets folded to form 20 leaves or 40 pages.
2. a book of this size.
Symbol: 20mo, 20°
—
adj.
in twentymo. Also called
vigesimo. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.