Duplicate \Du"pli*cate\, v. t. [imp. & p. p. {Duplicated}; p. pr. & vb. n. {Duplicating}.] 1. To double; to fold; to render double. [1913 Webster] 2. To make a duplicate of (something); to make a copy or transcript of. --Glanvill. [1913 Webster] 3. (Biol.) To divide into two by natural growth or spontaneous action; as, infusoria duplicate themselves. [1913 Webster]