onset

US /ˈɑːn.set/
UK /ˈɑːn.set/
"onset" picture
1.

开始, 发作

the beginning of something, especially something unpleasant

:
The onset of winter brought cold weather.
冬季的开始带来了寒冷的天气。
Early onset of the disease makes it harder to treat.
疾病的早期发作使其更难治疗。