mass noun
1- the action of killing oneself intentionally自杀：
he committed suicide at the age of forty
他40岁时自杀了
count noun gun control laws may reduce suicides.枪支管制法可能会减少自杀。
1.1
- count noun a person who does this自杀者。
1.2
- a course of action which is disastrously damaging to oneself or one's own interests自杀性行为, 自毁：
it would be political suicide to restrict criteria for unemployment benefit.
限制领取失业救济金的标准无异于政治自杀。
1.3
- as modifier relating to or denoting a military operation carried out by people who do not expect to survive it（军事上的）自杀性行为, 与对方同归于尽的行为：
a suicide bomber.
自杀轰炸机。
词源
mid 17th cent.: from modern Latin suicida 'act of suicide', suicidium 'person who commits suicide', from Latin sui 'of oneself' + caedere 'kill'.