octodecimos

1 definition found

octodecimos - Collaborative International Dictionary of English v.0.48 :

  Octodecimo \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[deg], and called eighteenmo.
     [1913 Webster]