1) Any four copies 2) Fourfold 3) Multiple 4) Quadruple 5) Quadruplex 6) Reproduce fourfold 7) To make fourfold 8) To quadruple 9) To replicate four times 1) Multiple 2) Quadruple 3) Quadruplex 
• (v. t.) To make fourfold; to double twice; to quadruple. • (a.) Raised to the fourth power. • (a.) Fourfold; doubled twice; four times repeated; as, a quadruplicate ratio, or a quadruplicate proportion.
Quad·ru'pli·cate transitive verb [ imperfect & past participle Quadruplicated ; present participle & verbal noun Quadruplicating .] [ Latin quadruplicatus , past participle of quadruplicare , from quadruple ... fou...
[n] - any four copies 2. [v] - reproduce fourfold
quadruplex adjective having four units or components; `quadruple rhythm has four beats per measure`; `quadruplex wire` noun any four copies; any of four things that correspond to one another exactly; `it was signed in quadruplicate`