• Webster's Revised Unabridged Dictionary
    • n Vigesimo-quarto 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 24°.
    • a Vigesimo-quarto Having twenty-four leaves to a sheet; as, a vigesimo-quarto form, book, leaf, size, etc.
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Century Dictionary and Cyclopedia
    • vigesimo-quarto Said of a section of twenty-four pages in a book, on a sheet, or in form of type. Usually called twenty-four-mo.
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Chambers's Twentieth Century Dictionary
    • adj Vigesimo-quarto formed of sheets folded so as to make twenty-four leaves
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Webster's Revised Unabridged Dictionary
L. vigesimus quartus, twenty-fourth. Cf. Duodecimo
Chambers's Twentieth Century Dictionary
L. vigesimusviginti, twenty.