Octodecimo

Octodecimo - Other Definitions

• (a.) Having eighteen leaves to a sheet; as, an octodecimo form, book, leaf, size, etc.
  
  
• (n.) 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.