Although it is nearly impossible to define love, I believe could be sort of like this:

Love is when you realize that no one is perfect, but you are perfect for each other.
Love is when you would never change anything about that other person.
Love is feeling like your heart is breaking when you miss them.
Love is the ability to be yourself with them. To laugh, to cry, to act like a four-year-old, to get into mischief, and never feel embarrassed. Love is when you can't stop thinking about that other person. Love is when that person's happiness is more important than your own. Love is when you would sacrifice anything for that person. When you get butterflies when you are around them for only a couple of seconds. Love is when you miss that person when they are gone. Love is accepting the good and the bad from that person. Love is when that person is the last thing on your mind at night and the first thought in the morning Love has many different definitions.

Feel free to comment on what you think love is.