It is something which you can do beyond your expectations it means to cross the boundary, it means to challenge yourself, it also means to go beyond your limitations
I would explain with an example: if you want to learn Japanese in 3 months and you do it in 1.5 month then you have challenge yourself and gone beyond your expectation and you have defeated your limitation .
The answer is to make a connection between the character in <em>Pilgrims Progress </em>and muckraking journalists. I know that this is the answer because I take English and took a quiz asking me about this and it was the right answer.
