in quadruplicate: four times over, in four copies

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

Happening every four years. / Lasting for four years.

A four-year period, a quadrennium.

the theory that changes in prices and the value of money vary with changes in the amount of money in circulation

The New Zealand falcon, Falco novaeseelandiae, formerly also Hieracidea novae-hollandiae.

(law) An estate which has an annexed qualification; a base fee.

a screw or worm gear having four equal threads and thus capable of being started in four places

Ownership that is not absolute and complete. / Property whose subject matter is by nature not permanent (as wild animals reduced to possession but not in captivity).

(physics) A constant used as a unit of measurement for particle spin, equal to Planck's constant divided by 2π.