A more thorough explanation:

Term: ad interim
Definition: Ad interim means temporarily or for the time being. It is a Latin term used in history.
Examples:

• The CEO resigned and the CFO was appointed ad interim until a new CEO was hired.
• The ad interim government was formed after the president's sudden death.

Ad interim is used to describe a temporary situation or arrangement. In the first example, the CFO was appointed temporarily until a new CEO was hired. In the second example, the ad interim government was formed after the president's sudden death until a new government could be elected.