In order to define love, you need to first clarify what "type" of love. The Ancient Greeks knew four different types of love! To clarify, here's an excerpt from Wikipedia:
Ancient Greek has the words philia, eros, agape, storge, and xenia.
Agape (????? agáp?) means love in modern-day Greek. The term s'agapo means I love you in Greek. The word agapo is the verb I love. It generally refers to a "pure," ideal type of love, rather than the physical attraction suggested by eros. However, there are some examples of agape used to mean the same as eros. It has also been translated as "love of the soul."
Eros (???? ér?s) (from the Greek deity Eros) is passionate love, with sensual desire and longing. The Greek word erota means in love. Plato refined his own definition. Although eros is initially felt for a person, with contemplation it becomes an appreciation of the beauty within that person, or even becomes appreciation of beauty itself. Eros helps the soul recall knowledge of beauty and contributes to an understanding of spiritual truth. Lovers and philosophers are all inspired to seek truth by eros. Some translations list it as "love of the body."
Philia (????? philía), a dispassionate virtuous love, was a concept addressed and developed by Aristotle. It includes loyalty to friends, family, and community, and requires virtue, equality, and familiarity. Philia is motivated by practical reasons; one or both of the parties benefit from the relationship. It can also mean "love of the mind."
Storge (?????? storg?) is natural affection, like that felt by parents for offspring.
Xenia (????? xenía), hospitality, was an extremely important practice in Ancient Greece. It was an almost ritualized friendship formed between a host and his guest, who could previously have been strangers. The host fed and provided quarters for the guest, who was expected to repay only with gratitude. The importance of this can be seen throughout Greek mythology—in particular, Homer's Iliad and Odyssey.