duplicate (?), a. [L. duplicatus, p. p. of duplicare to double, fr. duplex double, twofold. See Duplex.] Double; twofold.
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Duplicate proportion or Duplicate ratio (Math.), the proportion or ratio of squares. Thus, in geometrical proportion, the first term to the third is said to be in a duplicate ratio of the first to the second, or as its square is to the square of the second. Thus, in 2, 4, 8, 16, the ratio of 2 to 8 is a duplicate of that of 2 to 4, or as the square of 2 is to the square of 4.
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Duplicate (?), v. t. [imp. & p. p. Duplicated (?); p. pr. & vb. n. Duplicating.] 1. To double; to fold; to render double.
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2. To make a duplicate of (something); to make a copy or transcript of. Glanvill.
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3. (Biol.) To divide into two by natural growth or spontaneous action; as, infusoria duplicate themselves.
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