1. The act of responding.
2. A reply or an answer.
3. A reaction, as that of an organism or a mechanism, to a specific stimulus: a microphone's response to certain frequencies; response by the immune system to a pathogen.
a. Ecclesiastical Something that is spoken or sung by a congregation or choir in answer to the officiating minister or priest.
b. A responsory.
[Middle English respons, from Old French, from Latin respōnsum, from neuter past participle of respondēre, to respond; see RESPOND.]
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.