Cliche means, Overused expression : a word or phrase that has lost its original effectiveness or power from overuse. For example: Sweaty palms - in this phrase it does not mean that palms are sweat but it means "nervous". if you are not clear with that, here is an easy example! Time will tell:Time will not speak but it means that something will revealed or become clear over time!
Cliche is something that is often said or done, that has been overused; predictable. Examples: The movie "Mean Girls" is very cliche. The saying mentioned in the other comment "Its not you, it's me." has been used many times in movies, etc.