Onset
noun, verb ·Common ·High school level
Definitions
- 1 The initial phase of a disease or condition, in which symptoms first become apparent.
"the onset of schizophrenia"
- 2 (military) an offensive against an enemy (using weapons) wordnet
- 3 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."
- 4 the beginning or early stages wordnet
- 5 The beginning of a musical note or other sound, in which the amplitude rises from zero to an initial peak.
Show 3 more definitions
- 6 A setting about; a beginning.
"the onset of puberty"
- 7 Anything added, such as an ornament or as a useful appendage. obsolete
"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."
- 8 An attack; an assault especially of an army. archaic
"Heralds, from off our towers, we might behold From first to last, the onset and retire Of both your armies"
- 1 To assault; to set upon. obsolete
- 2 To set about; to begin. obsolete
Antonyms
All antonymsExample
More examples"Due to the early onset of winter this year, authorities are forecasting shortages of heating oil."
Etymology
From on- + set. Compare Old English onsettan (“to impose; oppress, bear down”). For semantic parallels for the meaning to assault, compare cognate Russian насе́сть pf (naséstʹ), наседа́ть impf (nasedátʹ).
Related phrases
More for "onset"
Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.