Love is such a used, abused, and misused word that people should possibly stay away from it.
How I would define it?
In essence, love is the basic experience of caring about another, of going out from myself toward the Other.
Love requires caring – not caring about what benefit or enjoyment I can gain from you, but finding joy in the very fact of your existence.
When I say “I love you,” the truthfulness of my statement depends on the size of the “I” and the size of the “you”:
The bigger the “I,” the smaller the love.
But if the “I” is smaller than the “you,” then we have the sense that we are dealing with love.
–Rabbi Adin Steinsaltz
From a talk by Rabbi Adin Steinsaltz given at Columbia University’s Center for the Study of Science and Religion