When that girl you like says that she just wants a platonic relationship, having a platonic definition will definitely help you figure out where you stand. Platonic relationships are those between people, usually opposite sex pairs, that are loving but are not romantic or sexual in any way. It's a fancy way of saying "just friends." Platonic love is warm and affectionate, but the participants, ideally, do not have any sexual attraction or feelings for one another.
The word "platonic" refers to the philosopher Plato. It comes from Plato's work "Symphonium." In this, he talked about Socrates' relationships with young students. It's interesting to note that the original Platonic definition referred to friendships between men, as women were not permitted to study with Socrates. Plato praised the loving relationships between the students, considering that non-sexual relationship the highest expression of love. In fact, Plato distinguished between sexual and non-sexual affection by using different words for each sentiment. "Eros" referred to sexual love, while "philia" referred to love between friends.
Nowadays, the definition of platonic most frequently indicates a relationship between a man and a woman. The word platonic was given its modern definition in Europe during the Renaissance. People feel the need to distinguish a relationship as platonic because it is frequently expected that men and women who share close relationships will have romantic feelings for one another.
Platonic relationships can be highly rewarding. However, if you are interested in pursuing a romantic relationship and she says she prefers to keep things platonic, you are probably not going to have any luck taking things further.