"Get things rolling" is a phrase that represents the initiation of a process or getting things started. Antonyms for this phrase could be phrases like "halt the progress," "put a stop to," "idle," "delay," or "stagnate." In other words, the opposite of getting things started would be to stop or slow down progress. This could be done intentionally or unintentionally, depending on the situation. While "getting things rolling" is usually associated with productivity and progress, the aforementioned antonyms are often seen as undesirable, as they impede progress and can lead to inefficiency and lack of motivation.