1. (noun)quadruplicate any four copies; any of fourthings that correspond to one another exactly
"it was signed in quadruplicate"
2. (adj)quadruple, quadruplicate, quadruplex, fourfold, four-fold having four units or components
"quadruple rhythm has four beats per measure"; "quadruplex wire"
3. (verb)quadruplicate reproduce fourfold
"quadruplicate the bill"