tr.v. dis·con·cert·ed, dis·con·cert·ing, dis·con·certs
1. To cause to lose composure; embarrass or confuse: He was disconcerted by the teacher's angry tone. See Synonyms at embarrass.
2. To frustrate (plans, for example) by throwing into disorder; disarrange.
[Obsolete French disconcerter, from Old French desconcerter : des-, dis- + concerter, to bring into agreement (from Old Italian concertare; see CONCERT).]
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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.