Swear in Definition 1 of 1Pro Tip 1/3Ceremonial Context Used in formal ceremonies where an individual takes an office or position. The mayor will be sworn in at city hall. Pro Tip 2/3Political Relevance Commonly involves political or governmental roles, like presidents or judges. After the election, the chancellor was sworn in promptly. Pro Tip 3/3Oath Taking Involves the act of taking an oath to promise to fulfill duties faithfully. The new recruits were sworn in after completing their training.