a. Equal, as in value, force, or meaning.
b. Having similar or identical effects.
2. Being essentially equal, all things considered: a wish that was equivalent to a command.
a. Capable of being put into a one-to-one relationship. Used of two sets.
b. Having virtually identical or corresponding parts.
c. Of or relating to corresponding elements under an equivalence relation.
4. Chemistry Having the same ability to combine.
5. Logic Having equivalence: equivalent propositions.
1. Something that is essentially equal to another: "The hand is not the biological equivalent of a hammer or a screwdriver; the hand is a multipurpose tool like a Swiss Army knife" (Jonathan Gottschall).
2. Chemistry Equivalent weight.
[Middle English, from Late Latin aequivalēns, aequivalent-, present participle of aequivalēre, to have equal force : Latin aequi-, equi- + Latin valēre, to be strong; see wal- 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.