I could distinguish nothing in the darkness and was scared to death.

distinguish 是动词，意思是"区分、辨别、辨认"，指能够识别出事物之间的差异或特征。这个词由前缀 dis-（表示"分开"）和词根 stinguere（拉丁语，意为"刺、戳"）组成，字面意思是"通过标记来分开"，引申为"区分"。