It's a big question, isn't it?
Is it the answer to the ultimate question of life, the universe, and everything? No, that's not it, actually.
We're still trying to figure it out, but our current working definition is:
Meaning as a verb, Meaning as a noun, or maybe just Meaning as a really good excuse for not doing the laundry?
If you're still unsure, try reading The Meaning of Life Book for some insight, or better yet, try the meaning for yourself!