The notorious backbiter was finally shunned by everyone for spreading harmful gossip.

backbiter 是由动词 backbite（背后中伤）加后缀 -er 构成的名词。backbite 由 back（背后）和 bite（咬）组成，字面意思是"从背后咬人"，比喻"背后说人坏话"。 backbiter 指"喜欢在背后说人坏话的人"，即"背后中伤者"。