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.
To put to an oath; to cause to take an oath; to administer an oath to; -- ofetn followed by in or into; as, to swear witnesses; to swear a jury; to swear in an officer; he was sworn into office.