His report was completely unembellished, just the plain facts.

unembellished 是由前缀 un-（表示"不、非"）和动词 embellish（装饰、润色）的过去分词 embellished 组合而成。embellish 来自法语，原意是"美化"。unembellished 字面意思是"未经装饰的"，引申为"不加修饰的、朴实的"。