A more thorough explanation:

An interim trustee is a trustee appointed to perform all the functions and duties of a trustee until the regular trustee is selected and qualified. This term is commonly used in bankruptcy cases.

Before the meeting of creditors, the interim trustee often preliminarily investigates the debtor's assets and financial affairs. For example, if a company files for bankruptcy, an interim trustee may be appointed to manage the company's assets until a permanent trustee is appointed.