Webster's 1913 Dictionary
SEXTODECIMO
Sex `to *dec "i *mo, a. Etym: [L. sextus-decimus the sixteenth; sextus the sixth (fr. sex six ) + decimus the tenth, from decem ten. See - mo. ]
Defn: Having sixteen leaves to a sheet; of, or equal to, the size of one fold of a sheet of printing paper when folded so as to make sixteen leaves, or thirty-two pages; as, a sextodecimo volume.
SEXTODECIMO
Sex `to *dec "imo, n.; pl. Sextodecimos (.
Defn: A book composed of sheets each of which is folded into sixteen leaves; hence, indicating, more or less definitely, a size of a book; -- usually written 16mo, or 16º.
New American Oxford Dictionary
sextodecimo
sex to dec i mo |ˌsekstəˈdesəˌmō ˌsɛkstəˈdɛsəmoʊ |(abbr.: 16mo ) ▶noun ( pl. sextodecimos ) a size of book page that results from folding each printed sheet into sixteen leaves (thirty-two pages ). • a book of this size. ORIGIN late 17th cent.: from Latin sexto decimo, ablative of sextus decimus ‘sixteenth. ’
Oxford Dictionary
sextodecimo
sextodecimo |ˌsɛkstə (ʊ )ˈdɛsɪməʊ |(abbrev.: 16mo ) ▶noun ( pl. sextodecimos ) a size of book page that results from folding each printed sheet into sixteen leaves (thirty-two pages ). • a book of sextodecimo size. ORIGIN late 17th cent.: from Latin sexto decimo, ablative of sextus decimus ‘sixteenth ’.
The Wordsmith Dictionary