What is it?
To me it is what I feel when I look at my children growing up.
The feeling I get deep inside when I look upon our nation's flag unfurled, waving in the wind.
And knowing that I am a part of something that has help to keep this great country of ours safe for over 200 years.
I, like so many others, have paid the price of freedom in blood, sweat and tears. And we take Pride in God, Country and Corps.
We are Warriors and this is our soung.

http://www.youtube.com/watch?v=Sam4lq2WHos

I like this definition, which I found by Googling "define: pride" -

Thanks Gunny, hadn't seen that before. Semper Fi!