Unaltered means unchanged. If your parents’ poor opinion of your boyfriend remains unaltered no matter how polite he is or how early he brings you home, it may be because of his tattoos and motorcycle.
Unaltered is the opposite of altered, meaning to adjust or change. If you meet a friend you haven't seen in ten years, and she looks the same as you remember, you might exclaim at how unaltered she seems. If you buy a pair of pants that need to be hemmed, you won't be able to wear them in their unaltered state.
