1530s, "attack, assault," from on + set (n.); compare verbal phrase to set (something) on (someone). Weaker sense of "beginning, start" first recorded 1560s. Figurative use in reference to a calamity, disease, etc. is from 1580s.
权威例句
1. The sudden onset of winter caused havoc with rail and air transport.
冬天的突然降临让铁路和航空运输系统陷入混乱。
2. Most of the passes have been closed with the onset of winter.
冬天来临,大部分关口均已关闭。
3. The drug must be taken from the onset of the infection.
这种药必须在感染的最初期就开始服用.
4. The onset of depression often follows a traumatic event.
抑郁症发作常常发生在遭受创伤之后.
5. His first hit record marked the onset of an astonishing career.