Okay, that's a great way to describe a word, by using the word. But what is it in YOUR life that has been meaningful? Not a flame, so don't go off on me. I don't know you, so I can't have an agenda against, or for, you. What is it about your life that would make a difference if it ended today?
Cswillson, for me their's not just one thing that gives me meaning to my life. Their's a number of things that gives me the feeling that my life is meaningful. My family is one factor. When I do well, it helps them. Also, doing volunteer work to help individuals as well as the community is meaningful to me. And learning something new each day helps me as well.
Look for meaning in anything and you will find it. That's kind of the human condition, the search for meaning. It's one of the many things that "separates" us from animals, the ability to ask Why? To me, the simplest answer to your question is: Does Life really have to have a meaning? Is it not glorious and elegant enough to know that we exist in our current form purely as the result of an absurdly long chain of chance occurrences, miniscule changes and adaptations caused by random genetic mutation resulting in better adaption to changing environments? To me that is far more satisfying than "God did it" or "The flying Spaghetti Monster danced the funky chicken and BAM! Here we are!"