octodecimo
十八開紙,十八開
Oc·todec·i·mo a. Having eighteen leaves to a sheet; as, an octodecimo form, book, leaf, size, etc.
Oc·to·dec·i·mo, n.; pl. Octodecimos A book composed of sheets each of which is folded into eighteen leaves; hence; indicating more or less definitely a size of book, whose sheets are so folded; -- usually written 18mo or 18°, and called eighteenmo.
◄ ►