-ous
/-əs/
"ous" is a 3-letter English headword indexed on PlainSpell.
The verdict
“-ous” is uncommon English (outside the top frequency list), classed as a suffix. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 4
- letters
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Used to form adjectives from nouns, to denote:
Corpus desk
Index EN-ous · -ous · English
-ous · unranked · 0 variants · 0 confusables
- FREQ-UNRANKED Unranked
- LEN-MID 4 letters
- VOW-2 2 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-THIN "-" thin
- PHOTO-UNK Peer pending
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.
| Property | Value |
|---|---|
| Headword | -ous |
| Language | English |
| Part of speech | Suffix |
| IPA | /-əs/ |
| Letters | 4 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “-ous” sits in English frequency
Rare enough to double-check
-ous is uncommon English outside the top frequency list, classed as asuffix, transcribed /-əs/. Rarity is why readers land here mid-draft. 4 senses are on record.
Zero misspellings are on record for -ous in our index, typically a sign the spelling maps closely to how the word sounds. This headword has no recorded confusable partner, suggesting its spelling stands apart enough that readers rarely confuse it with something else.
Etymologically, the entry records: From Middle English -ous, from Old French -ous, -os, -us, from Latin -ōsus (“full of”). Doublet of -ose and -wise in unstressed position. Many English adjectives ending in -ous were taken from preexisting French or Latin adjectives that end in one of the ab… The correct English form is -ous, spelled --O-U-S.
Definition
- 1Used to form adjectives from nouns, to denote:
- 2Used to form adjectives from nouns, to denote:
- 3Used to form adjectives from nouns, to denote:
- 4Used in chemical nomenclature to name chemical compounds in which a specified chemical element has a lower oxidation number than in the equivalent compound whose name ends in the suffix -ic. For example sulphuric acid (H₂SO₄) has more oxygen atoms per molecule than sulphurous acid (H₂SO₃). See Inorganic nomenclature.
Etymology
From Middle English -ous, from Old French -ous, -os, -us, from Latin -ōsus (“full of”). Doublet of -ose and -wise in unstressed position. Many English adjectives ending in -ous were taken from preexisting French or Latin adjectives that end in one of the above suffixes (e.g. envious corresponds directly to Old French envious which in turn corresponds directly to Latin invidiōsus). In addition, -ous (or the variant form -ious) has at times been attached to English nouns to form derived adjectives that lack precedents in French or Latin, such as slumberous from slumber or blizzardous from blizzard. It has also been used in some cases as a means of adapting adjectives borrowed from Latin that originally ended simply in -us, -a, -um (for example, obvious and previous are derived from Latin obvius and praevius, not *obviōsus or *praeviōsus).
This word in other languages
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA). See the methodology for how each field is sourced and updated.
PlainSpell is rendered directly from structured Wiktionary extracts and open word-frequency lists, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 6, 2026. Primary sources: Wiktionary (via kaikki.org) and FrequencyWords.
Frequently Asked Questions
How do you spell "-ous"?
What does "-ous" mean?
How do you pronounce "-ous"?
What is the origin of the word "-ous"?
Is PlainSpell free to use?
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.