Rain check: This expression was said to originate from open air market transactions where significant rain would usually require a vendor to pack up and leave. This term is also based on issuing of tickets to claim on property at a later time. Before 1889, if any US Baseball match was cancelled due to rain, they will issue new tickets for the postponed match. Abner Power add a detachable stub to the ticket on that year. That stub is called Rain Check. From that year onwards, it quickly became the standard practice among the major leagues.

In present times, people use it as a polite way to turn down an invitation with the implication that another time would be possible.