Sextodecimo
Sextodecimo , adjective
[Latin sextus-decimus the sixteenth; sextus the sixth (from sex six) + decimus the tenth, from decem ten. See -mo.]
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 ({not transcribed}) , noun
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 16°.