quadruplicate

adj

1. (not-comparable)having four parts

   “The small schools might specialize upon the type locally most desirable, the larger might group its triplicate (or quadruplicate) system of sustained and serious courses about a common Library […]”

2. (not-comparable)four times over, multiplied by four

   “[…] Fortune, who delights in making the miner or the lumber-man a quadruplicate millionaire and in "busting" the railroad king.”

noun

1. in quadruplicate: four times over, in four copies

   “Four times Cupid's debtor I-- / Bankrupt in quadruplicate.”

verb

1. To replicate four times; to make fourfold; to quadruple.