DECIMOSEXTO

Dec`i*mo*sex"to, n. Etym: [Prop., in sixteenth; fr. L. decimus tenth + sextus sixth.]

Definition: A book consisting of sheets, each of which is folded into sixteen leaves; hence, indicating, more or less definitely, a size of book; -- usually written 16mo or 16º.

Dec`i*mo*sex"to, a.

Definition: Having sixteen leaves to a sheet; as, a decimosexto form, book, leaf, size.

Source: Webster’s Unabridged Dictionary 1913 Edition