A cliché is an overused phrase. Clichés should be avoided in university and research writing, as they can devalue your work in the eyes of the reader. Some examples are given below:

A legend in their own lifetime
A whole new ball game
At the end of the day
Better late than never
Get your act together
Hit the big time
In my humble opinion
In this day and age
It’s not over till it’s over
It’s not over till the fat lady sings
It’s not rocket science
Over the moon
The be-all and end-all
The bottom line
The name of the game
The show must go on
You can bet your bottom dollar
You name it

As always in language, this is a guideline rather than a hard-and-fast rule: A whole new ball game would be an apt title for a recent discovery in Meso-American studies, but a poorly chosen phrase to describe the impact of your most recent work on the field.