Middle-earth is the setting of much of J. R. R. Tolkien's legendarium. The term is equivalent to the term Midgard of Norse mythology, describing the human-inhabited world, i.e. the central continent of world of Tolkien's imagined mythological past. Tolkien's most widely read works, The Hobbit and The Lord of the Rings take place entirely in Middle-earth, and Middle-earth has also become a short-hand to refer to the legendarium or its "fictional-universe".
Within his stories, Tolkien translated the name "Middle-earth" as Endor (or sometimes Endórë) and Ennor in the Elvish languages Quenya and Sindarin respectively, sometimes referring only to the continent that the stories take place on, with another southern continent called the Dark Land.
Middle-earth is the central continent of Earth (Arda) in an imaginary period of the Earth's past (Tolkien placed the end of the Third Age at about 6,000 years before his own time), in the sense of a "secondary or sub-creational reality". Its general position is reminiscent of Europe, with the environs of the Shire intended to be reminiscent of England (more specifically, the West Midlands, with Hobbiton set at the same latitude as Oxford).
All that I held precious
All I treasured in this world
Was you
All that I had cradled
All I gave up for you
You, you
You consciously killed our future
Never breaking stride
God, it makes me nauseous
Just to think about you
Tasting other guys
I won't act as if
Nothing's wrong
But my healing has begun
Even though you broke my life
I'm still able to smile
No denial
Something' inside
Is keeping me alive
Right before it folded
Seems like everyone could see
But me
Bet you couldn't figure out
How to lose me
Easily
Won't dignify your decision
To suffocate my dream
Giving you the pleasure of believing you could
Put an end to me
While you prance about
Someone else
Won't feel sorry for myself
Living life alone tonight
I'm still able to smile
No denial
Something inside
Is keeping me
Keeping me Alive
I'm still breathing
I'm still breathing
Something inside
Is keeping me