What is "cup of coffee"

n. (context baseball English) When a minor league player comes up to the major league team for a short period of time.

A "cup of coffee" is a North American sports idiom for a short time spent by a minor league player at the major league level. The idea behind the term is that the player was only in the big leagues long enough to have a cup of coffee before being returned to the minors, or simply to describe a brief stint served with a professional team. The term originated in baseball and is extensively used in ice hockey, both of whose professional leagues ( MLB and the NHL) utilize extensive farm systems; it is rarely used in basketball or American football since neither the NBA nor NFL have implemented a true farm system.

One example of how this term is used in a sentence was during the 1996 film The Fan, in which Robert De Niro's character, a middle-aged former pitcher, says, "I was in the bigs for a cup of coffee myself until my arm went south."