RAIN CHECK

whats the meaning of "RAIN CHECK"

See Merriam-Webster -- www.merriam-webster.com/ dictionary/rain%20check If an event (an outdoor ball game) is canceled because of rain, a customer can get a "rain check" good for the next event. You can also use the expression to indicate you want to delay an event. Do it later. It is kinder than just saying no.

Do you want to go for coffee?
No. I'll take a rain check.