quadruplicate

(noun) any four copies; any of four things that correspond to one another exactly. Example: "It was signed in quadruplicate."

(verb) reproduce fourfold. Example: "Quadruplicate the bill."

(adj) having four units or components. Synonyms: quadruple, quadruplex, fourfold, four-fold. Examples: "Quadruple rhythm has four beats per measure." "Quadruplex wire."