having four parts / four times over, multiplied by four

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 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).

Abbreviation of quarto.