1: an act of offering to a deity something precious; especially : the killing of a victim on an altar
2: something offered in sacrifice
3 a: destruction or surrender of something for the sake of something else
b: something given up or lost
Without arguing with them, I want to include a bit more of what I believe "sacrifice" to mean.
# 3a gets close to what I'm thinking, but I'd like to take it a bit further. Jesus spoke of qualities that make someone a good person in Corinthians 13:13. He spoke of faith, hope, charity, and love; with love being the greatest of these. He didn't include "sacrifice", which I'm sure wasn't an oversight. I believe he wanted us to discover that through our human experience.
I tend to call it "shit or get off the pot". A little bit more earthy. What I'm talking about is the act of putting someone else's well being before your own. This act has elements of suicide in it, as well as martyrdom. It's not for the feint of heart, and can often result in one's own destruction.
Is there anything worth sacrificing for in such a manner? I say; "you're damn right there is!" There is deep within us a part that WILL NOT comprimise or allow something to happen to a person/people we care about, if we think it's wrong. It's not too different than a German Shepherd protecting their human child. We will fight (and bite) anyone attempting to do so.
I've had that experience. I hope you have too. I've sacrificed a 27 year career that I was very proud of, to save the life of a friend who was unable to speak for themselves. For me, it was a no-brainer. I don't believe I could have lived with myself if I hadn't. The sacrifice I made cost me a lot. What it cost others is in their own souls.
I LOVE the concept, and reality of "sacrifice!" I really do think it's made me more human than I could have ever been without it... I hope you'll consider it, if you ever need to.