tr.v. per·turbed, per·turb·ing, per·turbs
1. To disturb or confuse; make uneasy or anxious: I was perturbed by his off-color remarks.
a. To cause (a system) to become altered or imbalanced from a normal state: volcanic eruptions that perturbed the climate.
b. Physics & Astronomy To cause perturbation in (the orbit of a celestial body, for example) by gravitational interaction.
[Middle English perturben, from Old French perturber, from Latin perturbāre : per-, per- + turbāre, to throw into disorder (from turba, confusion, perhaps from Greek turbē).]
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.