So many people have so many different ways to define love, and I honestly think that there is no one true definition. There are as many definitions as there are people. Here's what Webster has to say:
Love: n. a profoundly tender, passionate affection for another person. A feeling of warm personal attachment or deep affection as for a parent, child or friend.
And here's what God has to say:
Love is patient, love is kind. It does not envy, it does not boast, it is not proud. 5 It does not dishonor others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. 6 Love does not delight in evil but rejoices with the truth. 7 It always protects, always trusts, always hopes, always perseveres.8 Love never fails. (1 Corinthians 13:4-8a)
What is it to me? Love is feeling perfectly comfortable with that person. It's laughing so hard you have tears running down your face. It's the fluttering in your stomach when you catch a glimpse of their face when you're not expecting it. It's the quivery feeling you get at night when you can't sleep because they're on your mind and the quiet emptiness you feel right after they leave. It's long conversations about the things that really matter. Love is all of this and so much more, and what makes love so special is the fact that you can't possibly put all of it into words.