Undefinable

What is love?
It is an eternal emotion
Not a fading feeling
Love is sitting in the kitchen for hours
As she stresses out over Algebra homework
And you remind her how beautiful she is
Even though shes crying, her hair is a mess, and her eyes are bloodshot
Love is making all those extra trips that are miles out of your way
Wasting gallons of gas (though you don't see it that way)
And 'dressing up' just for her
So she doesn't have to miss her favorite school dance
Love is sending her little 'just because' texts
Leaving random 'I love you' messages
And sneaking over to her house to see her through her window
Just in hopes of making her feel better faster
Love is not an affliction
Cannot be cured
Cannot be fallen out of
Love is real
True
Never-ending
Never slowing
But how do you define something so undefinable?