After the unfair verdict, he was beside himself with anger.

was 是 be 动词的过去式，表示状态。 beside 是介词，意思是"在...旁边"。 himself 是反身代词，指"他自己"。 beside himself 是一个固定短语，字面意思是"在自己旁边"，引申为"失去自控、极度激动"的状态，常用来形容愤怒、悲伤等强烈情绪。