The natural American thing is to think of love as a kind of gauzy sentiment. This isn’t the worst definition. It roughly corresponds to day to day reality. But where it breaks down, it breaks down badly. It is impossible to square with God’s nature. And it makes you try to force yourself to feel gauzy sentiment about people, which is silly.
The old school Catholic definition of love is willing the good of another. That also isn’t a bad definition. It gets at something important and turns you away from making your own feelings your purpose to making other people your purpose. It also helps to explain the well-known phenomenon where serving people gradually leads you to feeling sentiment for them.
But the best definition is that love is delighting in the good of another. Love is relishing.