Duplex

[Lat., from duo, two, and plicare, to fold.] Double; twofold; as, a duplex escapement. Duplex ratio, ( du'pleks ra's he-o,) n. (Math.) The ratio of the squares of two quantities, or the square of their ratio. -n. A double or second copy: a copy; a transcript; as, a duplicate of a letter. - Another corresponding to the first, or a second thing of the same kind; as, a dupli cate key. -v. a. [Lat. duplico, duplicatus.] To double; to fold; to make a transcript or counterpart of; as, to duplicate ideas.