This silly diagram does pull apart the word nicely, but it really isn't a definition per se.

Polyamory is the practice of having multiple open, honest loving relationships. Yes, that isn't as pretty as the picture above, but hey...

All of those words are key. Honest is important, in any relationship, mono or poly, what matters is that a relationship(s) work for everyone involved, that's what makes the relationship valuable--that it represents a common positive good.

It's a fairly complex term, and there's a lot of connotation that goes along with it as well as strict denotation. While there is a small area of overlap (in my opinion) with the term swinging, the polyamory community feels very diffierent (in my experience) than the swing community. The poly community seems to have a higher breadth of orientations in it, whereas swingers tend to be straight, with some encouragement for female (but never male) bisexuals. That alone disinterests me, but a bigger difference is the focus, polyamory is really about multiple relationships, as opposed to multiple sexual partners. Both are fine, but one works for me a lot better than the other.