Just a heads up, this contains spoilers to Tasogare Otomoe x Amnesia, so if you don't want to be spoiled, watch the anime and come back to read this. Otherwise, just continue what you're doing and enjoy.
Sacrifice comes from a religious bases meaning, "An act of slaughtering an animal or person or surrendering a possession as an offering to God or to a divine or supernatural figure.", used in the context of Tasogare Otome x Amnesia, the town that Yuuko lived in 60 years ago had a plague spreading around, killing several of the towns people. It had gotten to the point where the leaders of the town were on their last hope of surviving it and ended up misrepresented that spreading of disease as a curse from god which needed a human sacrifice to lift it.
There had to be someone to sacrifice and Yuuko was the one chosen. Sadly she was chosen by Asagi, one of the friends Yuuko took care of since, whom was one of the many effected by plague. The way Asagi chose Yuuko was completely on accident, since the leaders said the first name Asagi uttered, because she is the messenger from god, would be the sacrifice. Yuuko didn't even know that information and thought Asagi was the sacrife, so she tried to save Asagi, which made Asagi yell out Yuuko's name and it went down hill from there.
I never considered sacrifice to be anything noble or honorable, in terms of not having a choice yourself, because majority of the time it is the other people being selfish on your expense and while you just end up feeling like a pawn. It's no different in Yuuko's case because the towns people were completely despite and selfish which made Yuuko resent most, if not all, of the town for what happened to her being locked in that shine and starving to death.
I guess you could say I'm more pissed that people gave into superstition rather than try to find an evidence based solution. In the end, no one in the town was taught a lesson in human decency and all that was left is the grudge that formed Shadow Yuuko.