onset

The initial phase of a disease or condition, in which symptoms first become apparent.

the onset of schizophrenia

In mild cases of hypergonadism prior to puberty, the onset of physical and mood changes may not be abnormally early or significant enough to cause any psychological or long-term physical complications.

The initial portion of a syllable, preceding the syllable nucleus.

The only regular sources for Sardinian *θ are Lat. ci̯ and ti̯, which are absent from Latin onsets. This means that the substantial number of words starting in *θ, discussed in § 3 – 7, cannot regularly continue a Latin form.

The beginning of a musical note or other sound, in which the amplitude rises from zero to an initial peak.

A setting about; a beginning.

the onset of puberty

There is surely no greater wisdom than well to time the beginnings and onsets of things.

Anything added, such as an ornament or as a useful appendage.

And will with deeds requite thy gentleness: And, for an onset, Titus, to advance Thy name and honourable family, Lavinia will I make my empress.

To assault; to set upon.

To set about; to begin.