Onset

Part of speech: noun

Pronunciation: /ˈɒnˌsɛt/

Definitions

1. The beginning or initial stage of something, especially something unpleasant or a medical condition
2. The occurrence or starting point of an event or condition often characterized by its initial and sometimes adverse effects
3. A beginning phase or arrival of a situation, typically associated with challenges or troubles

Etymology: The noun "onset" is a compound of "on" and "set," and its earliest sense was aggressive rather than gentle: to attack or bear down upon someone. Old English had a verb "onsettan" meaning to impose upon, oppress, or assault, and English kept that sense of forceful advance for centuries. The idea of a force pressing down on you is still visible in the modern meaning of a sudden, unwelcome arrival. The softer sense of a beginning emerged later, and it is the one most people now use. When an onset is a start, it is often the start of something hard, such as an illness, a storm, or a crisis. A parallel exists in Russian, where "naséstʹ," meaning to descend upon or attack, shows the same movement of one thing bearing down on another.

Synonyms: beginning, start, commencement, initiation, outset

Antonyms: conclusion, end, termination, finish, cessation