/ Dictionary / Index S sixteenmo: Meaning and Definition of Find definitions for: six•teen•mo Pronunciation: (siks'tēn'mō), [key] — n., pl. adj. -mos, —n. Also calleda book size (about 4×6 in.; 10×15 cm) determined by printing on sheets folded to form 16 leaves or 32 pages. a book of this size. Symbol: 16mo, 16° —adj. printed, folded, or bound in sixteenmo; sextodecimo. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. 16-gauge sixteenpenny Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language