The Latin phrase ad interim (abbr. ad int., literally "in the time between") means "in the meantime" or "temporarily".
Examples from classic literature:
No; but she has become queen of Paris, ad interim. and since she could not venture at once to establish herself in the Palais Royal or the Tuileries, she is installed at the Hôtel de Ville, where she is on the point of giving an heir or an heiress to that dear duke.
The abbreviation a.i. is used in job titles. E.g. Director of Operations, a.i.