"Grind to a halt" is a commonly used idiom that refers to a sudden stop or cessation of something that was previously in motion. To express this idea in other words, one can use synonyms such as "come to a standstill," "halt abruptly," "cease to move," "stop dead in its tracks," "grind to a stop," or "hit a brick wall." These phrases convey the same sense of a sudden and unexpected stoppage, whether it be in the context of a project, a vehicle, or some other type of process. By using these alternate phrases, one can add variety and clarity to their writing or speaking.