on earth

1. like nothing on earth . Incomparable. For example, That perfume smells like nothing on earth , or Her new hair color is like nothing on earth . [c. 1900]

2. Also, in creation ; in the world . Ever, anywhere, of all possible things. These phrases are all used for emphasis in questions or, less often, in a negative context. For example, What on earth is he doing with a spade? or Where in creation did that child go? or How in the world do you expect me to carry all those bags? [Late 1700s]