onset

/ˈɒnˌsɛt/

//ˈɒnˌsɛt// noun

By · According to Wiktionary data (CC BY-SA) ·

"onset" is a 5-letter English headword indexed on PlainSpell.

The verdict

“onset” has 7 generated spelling variants in the English index at frequency #10,900. The variants make it a useful spelling check.

#10,900
frequency rank, English
1,431
“O” headwords
7
tracked misspellings
10
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - The initial phase of a disease or condition, in which symptoms first become apparent.

Corpus desk

Index EN-onset · onset · English

onset · rank #10,900 · 7 variants · 10 confusables

  • FREQ-MID #10,900
  • LEN-MID 5 letters
  • VOW-2 2 vowels
  • CONFUS-MID 10 pairs
  • VAR-MID 7 variants
  • BOOK-MID 1,431
  • PHOTO-FINISH OG

Nearest frequency peer: OG (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Rank peers near misspelling magnet “onset”

Same rarity band: useful when a typo lands on a peer headword

corpus weight

What this shows “onset” sits among these FrequencyWords peers; misspelling depth is tracked separately in the edit-distance chart.

Source FrequencyWords open word-frequency list As of September 3, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

onset vs OST
0% similar
onset vs oust
60% similar
onset vs outset
67% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for onset
PropertyValue
Headwordonset
LanguageEnglish
Part of speechNoun
IPA/ˈɒnˌsɛt/
Letters5
Frequency rank#10,900
Misspellings tracked7
Confusable pairs10
SourceWiktionary (kaikki.org)

Frequency seat of misspelling magnet “onset”

Word frequency stretches from the small set of words we reach for constantly (left) out to the long tail barely used once in a while (right).onsetlands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Same rarity band neighbours include “OG” (#10,899), “occupational” (#10,898), “PE” (#10,902). Among 1,431 “O” headwords, “onset” is #10,900. Source: FrequencyWords open word-frequency list.

A misspelling magnet

The generator records 7 spelling variants around onset (IPA /ˈɒnˌsɛt/), anoun. Corpus frequency is #10,900 among 1,431 “O” headwords. Wiktionary lists 6 senses, so context still picks the gloss.

Our generated misspelling index lists 7 likely wrong-spelling variants for onset, with forms such as "noset", "onest", and "onnset". Each of these forms differs from the correct spelling by one small edit: a doubled letter, a dropped silent letter, or a substituted vowel. It also participates in 10 confusable-pair relationships, "OST", "oust", "outset", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.

Etymologically, the entry records: 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). The correct English form is onset, spelled O-N-S-E-T.

Definition

  1. 1
    The initial phase of a disease or condition, in which symptoms first become apparent.
  2. 2
    The initial portion of a syllable, preceding the syllable nucleus.
  3. 3
    The beginning of a musical note or other sound, in which the amplitude rises from zero to an initial peak.
  4. 4
    A setting about; a beginning.
  5. 5
    Anything added, such as an ornament or as a useful appendage.
  6. 6
    An attack; an assault especially of an army.

Recorded use

Wiktionary examples

These source excerpts show how onset appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. the onset of schizophrenia
  2. 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.

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).

This word in other languages

arremetida(Español)assaut(Français)Angriff(Deutsch)investida(Português)

Common misspellings

Also misspelled as:

  • noset
  • onest
  • onnset
  • onsett
  • onsset
  • onste
  • osnet

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of onset - expressed in single-character edits (insert, delete, or swap one letter). Bigger bars stand out at a glance; a one-edit slip is the hardest to catch.

noset2onest2onnset1onsett1onsset1onste2osnet2
Edit distance from "onset"

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "onset"?
"onset" is spelled O-N-S-E-T. The IPA pronunciation is /ˈɒnˌsɛt/.
What does "onset" mean?
As a noun, "onset" means: The initial phase of a disease or condition, in which symptoms first become apparent.
What words are commonly confused with "onset"?
"onset" is commonly confused with "OST", "oust", "outset". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "onset"?
The IPA (International Phonetic Alphabet) transcription for "onset" is /ˈɒnˌsɛt/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "onset"?
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). See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "onset", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 5 letters (nearest by frequency rank).

pixel#10,909motto#10,890monks#10,889props#10,912

Similar misspelling depth

Headwords with a similar count of attested misspellings (7 here; floor ≥5).

prose7 variantsrazor7 variantssteer7 variantsDamon7 variants

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list