a. The act or process of adapting.
b. The state of being adapted.
a. Something, such as a device or mechanism, that is changed or changes so as to become suitable to a new or special application or situation.
b. A composition that has been recast into a new form: The play is an adaptation of a short novel.
a. Change or adjustment in structure or habits by which a species becomes better able to function in its environment, occurring through the course of evolution by means of natural selection.
b. A structure or habit that results from this process.
4. Physiology The responsive adjustment of a sense organ, such as the eye, to varying conditions, such as light intensity.
5. Change in behavior of a person or group in response to new or modified surroundings.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.