tr.v. de·ranged, de·rang·ing, de·rang·es
1. To disturb the order, arrangement, or functioning of: an asteroid impact large enough to derange the climate.
2. To upset (normal condition or functioning, as of a bodily organ).
3. To cause to be psychotic or otherwise severely mentally unsound.
[French déranger, from Old French desrengier : des-, de- + reng, line (of Germanic origin; see sker-2 in the Appendix of Indo-European roots).]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.