on
/ɒn/adjective, adverb, preposition, verb, noun
on is spelled O-N: 2 letters and one syllable. It appears 8,128 times per million words in written English, the 13th most frequent word form (wordfreq, 2021 data). As an adjective, on means “In the state of being active, functioning or operating” (English Wiktionary, September 2026).
How many letters and syllables are in on?
| Letters | 2: O-N |
|---|---|
| Syllables | 1 (from its American pronunciation) |
| In writing | 8,128 times per million words; the 13th most frequent word form |
| Wrong spellings searched | none measured in search |
| Rhymes with |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is on?
On appears 8,128 times per million words in written English, the 13th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce on?
- UK /ɒn/
- [ɔ̟n] ~ [ɞ̠n]
- British /ɔn/
On has one syllable (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Back_ache-on.wav, En-au-on.ogg, En-us-on.ogg, Wikimedia Commons (author and licence on each file's page).
What rhymes with on?
5 words on PlainSpell end in the same sounds as on from its last stressed vowel (/ɒn/, British pronunciation):
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of on
- ons present, singular, he/she/it
- oning participle, present
- onning participle, present
- oned participle, past
- onned participle, past
- ohn
- æons plural
- a-
- an-
- π-ons plural
- πons plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does on mean?
The meanings the English Wiktionary records, quoted as written there (source below).
adjective
- 1
In the state of being active, functioning or operating.
All the lights are on, so they must be home.
- 2
Happening; taking place; being or due to be put into action.
We had to ration our food because there was a war on.
- 3
informalOf a person, used to express agreement to or acceptance of a proposal or challenge made by that person; most commonly with subject “you” (see you're on).
"Five bucks says the Cavs win tonight." ―"You're on!"
- 4
Fitted; covering or being worn.
Your feet will soon warm up once your socks are on.
- 5
Of a stated part of something, oriented towards the viewer or other specified direction.
The photograph shows the UFO side on.
- 6
UKinformalAcceptable, appropriate.
It's not fair to do that – it's just not on.
- 7
Possible; capable of being successfully carried out.
Climbing up that steep ridge isn't on. We'll have to find another route.
- 8
Available; remaining.
Smith is 25 points ahead with only 23 on.
adverb
- 1
To an operating state.
turn the television on
- 2
So as to cover or be fitted.
The lid wasn't screwed on properly.
- 3
Along, forwards (continuing an action), onwards.
The policeman moved the tramp on.
- 4
In continuation, at length.
and so on
- 5
Later.
Ten years on, nothing had changed in the village.
- 6
Of betting odds, denoting a better-than-even chance. See also odds-on.
That horse is twenty-to-one on, so you need to stake twenty pounds just to win one pound.
- 7
Of a ball, into a pottable position.
The black was previously unavailable, but in potting that red, he's now pushed the black on.
preposition
- 1
Positioned at the upper surface of, touching from above.
A vase of flowers stood on the table.
- 2
Positioned at or resting against the outer surface of; attached to.
He had a scar on the side of his face.
- 3
Covering.
He wore old shoes on his feet.
- 4
At or in (a geographical location or position).
The lighthouse that you can see is on the mainland.
- 5
At (a relative spatial position).
We live on the edge of the city.
- 6
Near; adjacent to; alongside; just off.
The fleet is on the American coast.
- 7
Aboard (a mode of transport, especially public transport, or transport that one sits astride or uses while standing).
on a bus, on a train, on a plane, on a ferry, on a yacht
- 8
In the direction of (some part of one's vessel), to within 45 degrees.
A ship was sighted on the port quarter.
- 9
ScotlandUKWithout.
verb
- 1
colloquialTo switch on.
Can you on the light?
noun
- 1
In the Japanese language, a pronunciation, or reading, of a kanji character that was originally based on the character's pronunciation in Chinese, contrasted with kun.
Most kanji have two kinds of reading, called "on" and "kun".
noun
- 1
Dated spelling of aeon.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
On in Spanish, French, German and Portuguese
| Language | Words |
|---|---|
| French | allumé , parti , encore , sur , au-dessus , à propos de |
| German | an, ein, eingeschaltet, angeschaltet , weiter , auf |
| Portuguese | ligado , destinar , na, no, sobre , em |
| Spanish | encendido, conectado , en, sobre , -ón |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does on come from?
From Middle English on, from Old English on, an (“on, upon, onto, in, into”), from Proto-West Germanic *ana, from Proto-Germanic *ana (“on, at”), from Proto-Indo-European *h₂en- (“on, onto”).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).