A synonmym for platonic: indeed I feel it is a superior word to platonic, especially in the context of human male-female relationships. This is based on my personal experience of dating many girls but not having any sex. As such, I used to describe these relationships to my guy friends as being purely platonic when in fact my intention was not always that, especially if the chick was bang-worthy. But now I feel Plato himself must have had more sexual action with women than I have that it is more appropriate to describe a word using my name rather than the great Plato. Hence the word santonic - to describe a non-sexual, philosophical, academic relationship between a male and a female. It can also be extended to same-sex relationship if the user so desires.
John: Man, I have been dating Mary for 5 years and I did not get any pussy yet.
Jack: Whoa dude, that is one santonic relationship.