v. swore (swôr), sworn (swôrn), swear·ing, swears
1. To make a solemn declaration, invoking a deity or a sacred person or thing, in confirmation of and witness to the honesty or truth of such a declaration.
2. To make a solemn promise; vow.
3. To use obscene or blasphemous language; curse.
4. Law To commit oneself by oath to giving evidence or testimony that is truthful.
a. To declare or affirm solemnly by invoking a deity or a sacred person or thing: swore on the Bible that he would tell the truth.
b. To say or affirm earnestly and with great conviction: I swear that I will pay you back.
2. To promise or pledge with a solemn oath; vow: He swore to do his duty. See Synonyms at promise.
3. To utter or bind oneself to (an oath).
4. Law To administer a legal oath to: All the witnesses have been sworn.
To use vulgar language against; curse:
1. To have great reliance on or confidence in: He swears by his personal physician.
2. To have reliable knowledge of; be sure of: I think she left early, but I couldn't swear by it.
3. To take an oath by: He swore by all the angels and saints of heaven.
To administer a legal or official oath to: swear in a mayor.
swear off Informal
To pledge to renounce or give up: She has sworn off cigarettes.
swear out Law
1. To attest to (an affidavit or complaint) by oath.
2. To swear to evidence under oath in order to obtain (a warrant for arrest).
[Middle English sweren, from Old English swerian; see swer- in the Appendix of Indo-European roots.]
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.