Take a rain check意思
"Take a rain check" is an idiomatic expression in English that means to postpone an activity or an invitation to a later time. The phrase is believed to have originated in the United States in the late 19th or early 20th century, when baseball games that were cancelled due to rain were rescheduled using a ticket that served as a voucher for the new date, which was called a "rain check."
Nowadays, the expression is used more broadly to mean that someone is declining an invitation at the present time but would like to reschedule for another occasion. It's often used in a polite way to save face or to avoid committing to a specific date without implying that one is not interested.
For example, if you were invited to a party but couldn't attend due to a scheduling conflict, you might say, "I'd love to come, but I'm sorry I can't make it. Can I take a rain check?" This means you're asking the person to invite you to a future event instead.