I could be right in thinking it means different things to different people,depending on what age they are. My children are now at an age where they and their friends date,and there seems to be new words and terminology involved around the whole thing. op,are you and your friend different ages?
having feeling for eachother two people have to want it to be in the relationship. willing to compromise. try to understand the other person point of view even if you dont agree always be willing to listen. having trust and faith is also a very good start.
Agreeing and wanting to be together - a mutual understanding that you are a couple. And usually agreeing boundaries i.e not seeing other people, or if open relationship, what is and isn't acceptable. I would have said being in love or loving each other very much as well though I suppose there are lots of LTRs where that isn't the case, sadly.
Having had a discussion about monogamy and whether or not you want/expect it and where the boundaries lie for you. Before that, though, an expectation that you will spend time with each other regularly ie at the end of one evening/afternoon/shag it's not wierd or outrageous for either one of you to say something like 'What shall we do tomorrow/next week'?
If it consists of amicable but never-discussed bumping into each other in the pub every couple of Saturdays and going to his or yours for a shag, it's not a couple-relationship and there are no 'rights' on either side.