IPA: /ʌnˈɔːltəd/
KK: /ʌnˈɔltərd/
Not changed or modified from its original form.
The document remained unaltered despite the many discussions about it.
Unaltered → It is formed from "un-" (meaning not) and "alter" (from Latin "alterare", meaning to change). The word "unaltered" means not changed or remaining in its original state.
Think of 'not' ('un-') changing ('alter') something — that's why unaltered means it has not been changed.