vigesimo-quarto
Vi*ges"i*mo-quar"to, a. Etym: [L. vigesimus quartus twenty-fourth. Cf. Duodecimo.] Defn: Having twenty-four leaves to a sheet; as, a vigesimo-quarto form, book, leaf, size, etc. Vi*ges"i*mo-quar"to, n.; pl. -tos (. Defn: A book composed of sheets each of which is folded into twenty- four leaves; hence, indicating more or less definitely a size of book so made; -- usually written 24mo, or 24º.