Vi·ges·i·mo-quar·to a. 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 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°.
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