On Earth

  1. Used for emphasis in questions or negative contexts, meaning 'at all' or 'of all possible things.' 2. (like nothing on earth) Incomparable; unlike anything else.

Examples:

  • What on earth is he doing with a spade?
  • That perfume smells like nothing on earth.

Origin: Late 1700s (sense 1); c. 1900 (sense 2)