What is Joy?

My pastor today was trying to define joy.  He had a weird sentence that I think was intentionally odd, so as to be memorable.  Something like Joy is how you go WITH as you travel THROUGH.  I actually don't think he stuck the landing.

But it got me thinking.  My definition of joy has always been 'meaning and purpose'.  In other words it's not about being happy (most of us can agree on that), so much as it's the stuff that makes you happy a lot of the time.  Because you can be sad and still have joy, like when someone close to you dies, but you believe they're going to be with Jesus.

I was talking with some friends afterwards, and I came up with another definition, which is 'a sense that you're on the right track'.  That resonated with all three of us.  And using that, you can have the 'joy of the Lord' - the sense that you're trusting in Him and He loves you and is guiding you.  But you can also have other kinds of joy, like career joy or girlfriend joy or Christmas joy - a sense that despite flaws or setbacks or whatever, you're mostly on the right track for meeting your goals or doing life together or enjoying the sense of giving that goes with the season.

So, that's what I'm thinking about joy.  What's your definition?