quad·ru·ple (kwŏ-drpəl, -drŭpəl, kwŏdr-pəl)
1. Consisting of four parts or members.
2. Four times as much in size, strength, number, or amount.
3. Music Having four beats to the measure.
A fourfold amount or number.
tr. & intr.v. quad·ru·pled, quad·ru·pling, quad·ru·ples
To multiply or be multiplied by four: quadrupled the order; quadrupled in size.
[From Middle English quadriple, fourfold amount, and quadruple, tooth with four roots, both from Old French quadruple, from Latin quadruplum, from neuter of quadruplus, fourfold : quadru-, quadri-, quadri- + -plus, -fold; see pel-2 in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.