A sacrifice is something given up for the sake of others, so anything sacrificial is connected to that selfless act. In some cultures, people were once thrown in volcanoes to appease the gods: this was a sacrificial ritual, because the person's life was taken for a higher purpose. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.