from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The page size (3 1/2 by 5 1/2 inches) that results when a printer's sheet is folded into 32 equal sections.
- n. A book composed of pages of this size.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A paper size, (3.75"-5" x 2.5"-3.125"), one thirty-secondth of an uncut free sheet.
- n. A book size, corresponding to the paper size.
thirty-two + -mo (Wiktionary)