onset

The time when something starts, often something unpleasant.

• The onset of winter brought snow.
• They left before the onset of darkness.
• The onset of puberty varies from child to child.

How to use it: onset of something (The onset of heavy rain delayed the match.)

Similar words: beginning, start

Opposites: end

Common phrases: onset of something, at the onset, sudden onset

The first stage of an illness or condition, when its signs start to appear.

• The onset of symptoms was sudden.
• Early onset of the disease can affect school life.
• She recorded the time of onset in the medical notes.

How to use it: onset of something (The onset of fever may be the first warning.)

Similar words: beginning

Common phrases: disease onset, early onset, onset of symptoms