The phrase "holding over" means to continue or extend something beyond its original time frame. Synonyms for this expression include "prolonging," "indefinitely extending," "keeping going," "extending beyond," "continuing past," and "surpassing the planned duration." Another way to convey the idea is to use the term "carrying over." Additionally, "expanding," "running over," or "stretching out" could also be used as synonyms for holding over. In essence, any term that suggests the continuation of an action or event past its expected stopping point could be used as a synonym for "holding over".