sui"oneself" + -cide

source: Jisatsu-自殺 on Toyhouse

1. the action of killing oneself intentionally:

自殺(行為) (!(1)具体例ではa ～/～s; その際しばしば修飾語を伴う. (2)時に〖名詞〗の前で形容詞的に用いる)

e.g. he committed suicide at the age of forty

e.g. drug-related suicides.

a person who commits suicide.

｟かたく｠ 自殺者

a course of action that is disastrously damaging to oneself or one's own interests:

｟比喩的に｠ 自殺［自滅］行為

e.g. it would be political suicide to restrict criteria for unemployment benefits.

as modifier relating to or denoting a violent act or attack carried out by a person who does not expect to survive it:

e.g. a suicide blast caused more deaths.

2. US a running drill consisting of a sprint to a set point (especially a line on a basketball court) and back to the start, immediately followed by additional sprints of lengthening distances:

e.g. we shot free throws and if we missed we ran suicides.

verb no object

intentionally kill oneself:

自殺する (!kill oneselfの方が一般的) .

e.g. he leaves the service and then suicides.

mid 17th century: from modern Latin suicidium ‘act of suicide’, suicida ‘person who commits suicide’, from Latin sui ‘of oneself’ + caedere ‘kill’.