onus

Name: onus, English Word Data
Creator: Wiktionary
License: https://creativecommons.org/licenses/by-sa/4.0/

/ˈəʊnəs/

//ˈəʊnəs// noun

By PlainSpell · According to Wiktionary data (CC BY-SA) · analyzed September 3, 2026

The verdict

“onus” sits in 20 confusable pairs (corpus #29,402) as a noun. The look-alike neighbours are the real trap.

#29,402
frequency rank, English: 1,431
“O” headwords: 4
tracked misspellings: 20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A legal obligation.

Corpus desk

Index EN-onus · onus · English

onus · rank #29,402 · 4 variants · 20 confusables

FREQ-MID #29,402
LEN-MID 4 letters
VOW-2 2 vowels
CONFUS-HIGH 20 pairs
VAR-LOW 4 variants
BOOK-MID 1,431
PHOTO-FINISH Ola

Nearest frequency peer: Ola (-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.

Oceania

70,602
Ola

70,600
onus

70,599
onyx

70,598
oppa

70,597
osteoporosis

70,596

What this shows Bars place “onus” against nearest ranked English headwords, not a reprint of the confusable-pair desk.

Visual similarity to commonly confused words

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

onus vs OS

0% similar

onus vs ou

50% similar

onus vs out

50% similar

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

Key facts for onus
Property	Value
Headword	onus
Language	English
Part of speech	Noun
IPA	/ˈəʊnəs/
Letters	4
Frequency rank	#29,402
Misspellings tracked	4
Confusable pairs	20
Source	Wiktionary (kaikki.org)

Corpus rank beside confusables of “onus”

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).onuslands here:

#29,402

#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 “Ola” (#29,401), “onyx” (#29,403), “oppa” (#29,404). Among 1,431 “O” headwords, “onus” is #29,402. Source: FrequencyWords open word-frequency list.

Easy to mix with look-alikes

The spelling risk for onus is neighbouring look-alikes ("OS", "ou", …), not just typos; it is anoun pronounced /ˈəʊnəs/. Frequency #29,402 among 1,431 “O” headwords. 5 recorded senses keep meaning in play.

Our generated misspelling index lists 4 likely wrong-spelling variants for onus, with forms such as "onnus", "onsu", and "onuss". 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 20 confusable-pair relationships, "OS", "ou", "out", and more, where similar look or sound leads writers to substitute one word for another in context.

Etymologically, the entry records: Etymology tree Proto-Indo-European *h₃enh₂- Proto-Indo-European *-os Proto-Indo-European *h₃énh₂os Proto-Italic *onos Latin onuslbor. English onus Learned borrowing from Latin onus (literally “burden”). The correct English form is onus, spelled O-N-U-S.

Definition

1
A legal obligation.
2
Burden of proof, onus probandi.
3
Stigma.
4
Blame.
5
Responsibility; burden.

Recorded use

Wiktionary examples

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

The onus is on the landlord to make sure the walls are protected from mildew.
The argument is founded on a principle which is now acknowledged to be universal; and the onus of disproof must lie with those who may be bold enough to take up the position that a region exists where at last the Principle of Continuity fails.

Etymology

Etymology tree Proto-Indo-European *h₃enh₂- Proto-Indo-European *-os Proto-Indo-European *h₃énh₂os Proto-Italic *onos Latin onuslbor. English onus Learned borrowing from Latin onus (literally “burden”).

This word in other languages

obligación(Español)responsabilité(Français)Pflicht(Deutsch)

Common misspellings

Also misspelled as:

onnus
onsu
onuss
ouns

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of onus - 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.

Edit distance from "onus"

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 "onus"?

"onus" is spelled O-N-U-S. The IPA pronunciation is /ˈəʊnəs/.

What does "onus" mean?

As a noun, "onus" means: A legal obligation.

What words are commonly confused with "onus"?

"onus" is commonly confused with "OS", "ou", "out". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.

How do you pronounce "onus"?

The IPA (International Phonetic Alphabet) transcription for "onus" is /ˈəʊnəs/. 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 "onus"?

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 "onus", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 4 letters (nearest by frequency rank).

onyx#29,403 oppa#29,404 Oahu#29,397 nous#29,396