The news report was so dreadful that I just had to switch it off.

dreadful 是形容词，由名词 dread（恐惧、害怕）加上后缀 -ful（充满...的）构成，意思是"令人恐惧的、可怕的"。在口语中常用来表示"糟糕的、极差的"，带有强烈负面评价的意味。