get a rain check

To refuse an offer or invitation but with the hope or promise that it can be postponed or accepted at a later date or time. I'm sorry, but I'll have to get a rain check for dinner this Saturday. Would next weekend work for you? A: "Wait, Steve's not coming?" B: "He had to get a rain check after his wife woke up violently ill." Any chance I can get a rain check? I would love to see you, but I am just swamped with work right now.