the.com/onset
The moment a thing stops being maybe and starts being definitely.
means The beginning or start of something, especially something forceful or unwelcome like an attack, illness, or storm.
from A straightforward English compound: "on" plus "set," built from the verb "set on" — to attack or assail. It originally carried that aggressive sense of forces being set upon a target, and the word still hangs around medicine and weather, places where things tend to begin by hitting you.
military rootOnce meant a violent rush against the enemy
sound scienceThe split second a note begins, measured in milliseconds
medical dreadDoctors track it to clock how fast disaster arrives
sudden vs gradualSymptoms acute or sneaky decide your whole diagnosis
linguisticsThe consonants before a syllable's vowel core
for instance
onset of covid-19 pandemic — december 2019 in wuhan, china with first confirmed cases
onset of great depression — october 29, 1929, stock market crash on black tuesday