What does the idiom a rat race mean?

Answer 1

The idiom "rat race" is used to mean a pointless activity that some person (or rodent) is being forced to do. It is based on the use of rats as lab animals, which often involves running them through mazes or other such exercises which might broadly be called rat racing. It serves no actual purpose for the rat, only for the researcher (and in many cases one can argue that there is also no purpose being served for the researcher either, if the research in question is poorly conceived). Many employees often feel that they are in a comparable situation, being made to do meaningless things by their employer. For some people, life seems to be just a rat race.

Answer 2

When someone says they are in the rat race, it means they feel they are in an endless "chase" to achieve or obtain something that often seems ultimately meaningless or pointless.