IPA: /ˌʌnɪmˈbɛlɪʃt/
KK: /ʌnɪmˈbɛlɪʃt/
Something that is plain and not decorated or enhanced in any way.
The room was unembellished, with only the basic furniture and no decorations.
Unembellished → It is formed from "un-" (meaning not) and "embellish" (from Old French *embellir*, meaning to make beautiful or to adorn). The word "unembellished" means not made beautiful or not adorned, indicating a plain or simple state.
Think of 'not' ('un-') making something 'beautiful' ('embellir') — that's why unembellished means something that is plain or simple.