OCTODECIMO

Etymology

Noun

octodecimo (plural octodecimos)

(paper, printing) A size of a sheet of paper resulting from folding and cutting a sheet of paper into eighteenths (3.5"-4.5" x 4.9"-5.9").

(printing) A book consisting of pages of that size.

Synonyms

• (paper size): 18mo, eighteenmo, 18º

• (book size): 18mo, eighteenmo, 18º, T

Source: Wiktionary

Oc`todec"i*mo, a. Etym: [L. octodecim eighteen. See Octavo, Decimal, and -mo.]

Definition: Having eighteen leaves to a sheet; as, an octodecimo form, book, leaf, size, etc.

Oc`to*dec"i*mo, n.; pl. Octodecimos (.

Definition: A book composed of sheets each of which is folded into eighteen leaves; hence; indicating more or less definitely a size of book, whose sheets are so folded; -- usually written 18mo or 18º, and called eighteenmo.

Source: Webster’s Unabridged Dictionary 1913 Edition