Definition of: swear

(swâr) v. swore (Obs. sware), sworn, swear·ing v.i.
1. To make a solemn affirmation with an appeal to God or to some deity, or with invocation of something held sacred, as in attestation of truth or proof of good intentions: He swore by all the gods.
2. To make a vow; utter a solemn promise.
3. To use profanity; invoke or mention sacred beings or things irreverently or blasphemously; curse.
4. Law To give testimony under oath.
—v.t.
5. To affirm or assert solemnly by invoking sacred beings or things.
6. To promise with an oath or solemn affirmation; vow.
7. To declare or affirm upon oath: to swear treason against a man.
8. To take or utter (an oath).
9. To administer a legal oath to.
—to swear by
1. To appeal to by oath.
2. To have complete confidence in.
—to swear in To administer a legal oath to.
—to swear off Colloq. To promise to renounce or give up: to swear off drink.
—to swear out To obtain (a warrant for arrest) by making a statement or charge under oath. [OE swerian]
—swear′er noun