What is "rain check"

n. (label en idiomatic) Any voucher or note from a merchant to a customer to provide an item the merchant has run out of at a later date for the item's current price, or (in a more literal sense) to provide a service at a later date.

1. n. a promise that an unaccepted offer will be renewed in the future

2. a ticket stub entitling the holder to admission to a future event if the scheduled event was cancelled due to rain

Rain check may refer to:

In baseball, a rain check is a ticket issued to spectators which admits them to the ballpark at a later date at no additional cost to the ticket holder. It is issued if a game is cancelled due to rain or other inclement weather, or if a game has been started but suspended due to inclement weather prior to the point of becoming an official game (five innings in Major League Baseball). Depending on the home team/league policy and the rescheduling of the game, the rain check may admit the ticket holder to watch the rained out game only on the rescheduled date, or it may allow the ticket holder to exchange his or her tickets for tickets of equal value to another game within a specified time frame.

Rain checks were originally separate tickets issued by the home team to spectators as they left the ballpark following a rainout. In modern times, the ticket to the rained out game serves as the rain check. The practice has been recorded since the 1870s – though it did not become generally established until the 20th century – and today the term " rain check" is used idiomatically to refer to any deferred promise.