12mo Definition

noun

(paper) Abbreviation of duodecimo, a page size (5"-5.5" x 7.125"-7.5")

Wiktionary
(printing) A book size using duodecimo-sized pages.
Wiktionary

Other Word Forms of 12mo

Noun

Singular:
12mo
Plural:
12mos

Origin of 12mo

  • 12 + -mo, for a twelfth of a sheet.

    From Wiktionary