Happiness?don't understand the question but..erm..here' goes..
I define happiness with love.Not just romantic love,but friends love.Love makes you happy,and happiness in return brings love =) I'm constantly around people who love me,whether my best buddies in the world,my family or just my internet friends and family =)
With risk of being a imitator, I say the same thing as Romi, I proably wouldn't had put the words like that myself, but that is actually how I do define happiness
I define happiness a few ways. It can just be how you generally feel. I think I'm happy most when I'm talking with Romi. She laughs at my jokes, and is overall there for me. Being with her is the best, and she always makes my day. When she isn't around to brighten my day, my friends take over. The way we stick together is like a force to be rekoned with ^_^ I love all my friends, and in return, knowing they know that makes me happy.
I see it as total contentment. You have all you could ever need, and you know that it will last. For most people, it's important to share the warmth with others, but some people only achieve happiness alone. The solitary life is a part of some people's contentment, so it lets them be happy.
I don't really think I know many happy people. Lots of people feel joy, that short-term happiness that will brighten a day but is gone in a few hours, but happiness is a long term thing. It's much harder to find happiness.