quadruple

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Consisting of four parts or members.
2. adj. Four times as much in size, strength, number, or amount.
3. adj. Music Having four beats to the measure.
4. n. A fourfold amount or number.
5. v. To multiply or be multiplied by four: quadrupled the order; quadrupled in size.

Century Dictionary and Cyclopedia

1. Fourfold; four times told.
2. n. A number, sum, etc., four times as great as that taken as the standard: as, to receive the quadruple of a given sum.
3. To make four times as much or as many; multiply by four; repeat four times; make, do, or cause to happen four times over.
4. To become four times as much or as many; repeat itself four times.
5. Consisting of four parts; completed in four separate or successive operations.

Wiktionary

1. adj. Being four times as long, as big or as many of something.
2. v. To multiply something by four times.

GNU Webster's 1913

1. adj. Fourfold.
2. n. four times the sum or number; a fourfold amount.
3. v. To multiply by four; to increase fourfold; to double; to double twice.
4. v. To be multiplied by four; to increase fourfold; to become four times as much.

WordNet 3.0

1. v. increase fourfold
2. adj. having four units or components
3. n. a quantity that is four times as great as another
4. n. a set of four similar things considered as a unit
5. adj. four times as great or many