This is the 3013th most frequent Chinese word.
自杀
"Self-killing; suicide."
The term 自杀 is used here as a verb (选择自杀) to describe the act of committing suicide due to external circumstances.
他因压力太大而选择自杀。
He chose to commit suicide due to immense pressure.
In this sentence, 自杀 is used as a noun to refer to the concept or topic of suicide.
自杀是一种需要关注的社会问题。
Suicide is a societal issue that requires attention.
The term 自杀 is used as a noun to represent the subject matter being discussed in the novel.