onset

The word “onset” means the point at which something, especially an illness or a change, first begins. In plain terms, the very beginning of something, especially when it develops or arrives — a disease, a season, a change.

“Onset” is pronounced ON-seht (/ˈɒnˌsɛt/ in IPA).

Here is “onset” used in a sentence: “Doctors caught the disease at its onset, before symptoms appeared.”

“Onset” is a noun.

The word “onset” comes from Old English. From on- + set, echoing the older Old English onsettan ("to press down upon, oppress").

“Onset” is an uncommon word in modern English.

“Onset” has 2 distinct senses listed in this dictionary. The most common is: the point at which something, especially an illness or a change, first begins.

Onset typically describes the first appearance of something, especially an illness, symptom, or change, and often carries a sense of something arriving or taking hold. Outset refers more generally to the very beginning of any event, plan, or period of time, without that same connotation of something starting to affect you.

In phonetics, the onset is the consonant sound or sounds that come before the vowel in a syllable. For example, in the syllable "stop," the onset is the "st" sound that precedes the vowel.

When talking about illness, onset refers to the point at which the disease or symptoms first begin to appear. Doctors often describe onset as "sudden" or "gradual" depending on how quickly the condition develops.