swear

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb 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.
• intransitive verb To make a solemn promise; vow.
• intransitive verb To use obscene or blasphemous language; curse.
• intransitive verb Law To commit oneself by oath to giving evidence or testimony that is truthful.
• intransitive verb To declare or affirm solemnly by invoking a deity or a sacred person or thing.
• intransitive verb To say or affirm earnestly and with great conviction.
• intransitive verb To promise or pledge with a solemn oath; vow: synonym: promise.
• intransitive verb To utter or bind oneself to (an oath).
• intransitive verb Law To administer a legal oath to.
• noun A swearword.

from The Century Dictionary.

• noun An oath.
• To affirm or utter a solemn declaration, with an appeal to God or to some superhuman being in confirmation of what is affirmed; declare or affirm something in a solemn manner by some sacred being or object, as the Bible or the Koran.
• To promise something upon oath; vow; make a promise in a solemn manner.
• To give evidence or make any statement on oath or with an oath; also, to declare solemnly, without an oath, as to the truth of something.
• To use profane language; be profane; practise profaneness; use the name or names of God irreverently in common conversation; utter profane oaths; curse.
• To be incongruous or inharmonious (with): followed by at: often said of colors.
• To utter or affirm with a solemn appeal to God, a divinity, or something held to be sacred for the truth of the declaration: as, to swear an oath.
• To promise in a solemn manner; vow.
• To put to an oath; cause to take an oath; bind by an oath: as, to swear witnesses in court; to swear a jury.
• To declare or charge upon oath: as, to swear treason against a man.
• To appeal to by an oath; call to witness.
• To utter in a profane manner.
• See sweer.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To affirm or utter a solemn declaration, with an appeal to God for the truth of what is affirmed; to make a promise, threat, or resolve on oath; also, to affirm solemnly by some sacred object, or one regarded as sacred, as the Bible, the Koran, etc.
• intransitive verb (Law) To give evidence on oath.
• intransitive verb To make an appeal to God in an irreverant manner; to use the name of God or sacred things profanely; to call upon God in imprecation; to curse.
• intransitive verb to place great confidence in a person or thing; to trust implicitly as an authority.
• intransitive verb [Slang] to make a solemn vow, or a serious resolution, to abstain from something.
• transitive verb To utter or affirm with a solemn appeal to God for the truth of the declaration; to make (a promise, threat, or resolve) under oath.
• transitive verb (Law) To put to an oath; to cause to take an oath; to administer an oath to; -- ofetn followed by in or into.
• transitive verb To declare or charge upon oath.
• transitive verb To appeal to by an oath.
• transitive verb to make oath that one is under the actual fear of death or bodily harm from the person, in which case the person must find sureties that he will keep the peace.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Heavy.
• adjective Top-heavy; too high.
• adjective Dull; heavy; lazy; slow; reluctant; unwilling.
• adjective Niggardly.
• adjective A lazy time; a short rest during working hours (especially field labour); a siesta.
• verb To be lazy; rest for a short while during working hours.
• noun A swearword.
• verb intransitive (transitive) To take an oath.