The Oxford dictionary on love has the more relevant entries as:
noun: An intense feeling of deep affection.The Oxford definition of "love" is lacking enough that it explains exactly why Christians often go back to the Greek word that can be rendered into English as agape: what Oxford means by "love" is only the tip of the iceberg for what Christians mean by it. Oxford limits love to a deep or intense affection; but affection comes and goes. Oxford's thoughts on love are (at best) a matter of the heart only or (less than that) just a passing hormonal phenomenon.
verb: To feel deep affection for (someone)
Christianity sees love as "heart, soul, strength, and mind": the heart is essential for Christian love, but "Heart" is only a fraction of what is involved. "Soul" refers to the wholeness of our being, so that agape-love seeks more depth or permanence than affection, with more spiritual depth than affection. "Strength" reminds us of the role of dedication and effort in increasing and strengthening our love, and with a call to build something more lasting than can be achieved by sentimentality. "Mind" rounds out our love with participation from our intellect, with contributions such as thoughtfulness and consideration. This thoughtful love is the foundation of wisdom: knowledge directed by love.
That's enough of definitions, though. Do we mean that God is capable of affection? Yes, we do, though it needs immediate follow-up because there is a school of thought that says that emotions are passions and imply mutability or weakness. Here's the thing: do emotions imply mutability or weakness by their essential nature, or do emotions get that reputation because humans are mutable and weak? If we take as a premise that "love", being generous in nature, is not weak, and that God, being divine in nature, is not mutable, then there is nothing unworthy of God in having a strong and immutable love. Imagine that is why he created: out of love. Now imagine that God has a strong and immutable love for what he has made, that leads him to work for the good of all he has made, and for restoring things to their original glory. Imagine that strong and immutable love includes you.
That's what we mean by "God is love."
I'd invite any newcomers to the blog who are interested in the topic to also skim through the posts that are tagged "love", or tagged "God's love in action".