She often felt a deep sense of rejection after being ignored by her peers.

rejection 是名词，来自动词 reject（拒绝）。re- 是前缀表示"回"，-ject 是词根表示"投掷"，字面意思是"扔回去"，引申为"拒绝"。 rejection 指"被拒绝的状态或感受"，常带有情感上的排斥和否定意味。