Webster's Revised Unabridged Dictionary · 1913

Mo

Mo (mō) , adjective, adverb, and noun

[Anglo-Saxon . See More.]

More; -- usually, more in number. [Obsolete]
An hundred thousand mo. — Chaucer
Likely to find mo to commend than to imitate it. — Fuller

Mo ({not transcribed})

(Chemistry) chemical symbol for the element molybdenum.

MO ({not transcribed})

abbreviation for modus operandi, manner of operating; -- often used to refer to the method an habitual criminal uses to perpetrate his crime.

-mo

A suffix added to the names of certain numerals or to the numerals themselves, to indicate the number of leaves made by folding a sheet of paper; as, sixteenmo or 16mo; eighteenmo or 18mo. It is taken from the Latin forms similarly used; as, duodecimo, sextodecimo, etc. A small circle, placed after the number and near its top, is often used for -mo; as, 16°, 18°, etc.