The exam results were crushingly bad, with almost no one in the class passing.

crushingly 是副词，由动词 crush（压碎、碾碎）加上副词后缀 -ingly 构成。crush 的本义是"压碎"，引申为"彻底击败、使崩溃"的意思。 crushingly 在这里表示程度极深，带有"毁灭性地、令人崩溃地"的意味，强调考试结果糟糕到令人难以接受的程度。