light year
/ˈlaɪt.jɪɹ/noun
light year is spelled L-I-G-H-T-Y-E-A-R: 9 letters and one syllable. As a noun, light year means “A unit of length used to measure extremely large distances, equal to approximately 9.46 trillion kilometres 10 trillion kilometres (10¹⁶ metres)…” (English Wiktionary, September 2026). The plural of light year is light years or light-years.
How many letters and syllables are in light year?
| Letters | 9: L-I-G-H-T-Y-E-A-R |
|---|---|
| Syllables | 1 |
| In writing | a phrase: the frequency list counts single words |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce light year?
- UK /ˈlaɪt.jɪə/
- US /ˈlaɪt.jɪɹ/
- /ˈläːt.jøː/
Light year has one syllable.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vininn126-light_year.wav, Wikimedia Commons (author and licence on each file's page).
Words people confuse with light year
Also written: lightyear (one word or two).
Sources: English Wiktionary (homophones, alternative spellings).
Forms of light year
- light years plural
- ly
- lightyear
- light-year
- light-years plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does light year mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
A unit of length used to measure extremely large distances, equal to approximately 9.46 trillion kilometres 10 trillion kilometres (10¹⁶ metres), equivalent to the distance light travels in one Julian year.
- 2
informalA very long way.
The marathon runner in the lead is light years ahead of the one at the back.
- 3
informalA very long time.
Some of Leonardo da Vinci’s inventions were light years ahead of their time.
noun
- 1
Alternative spelling of light year.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Light year in Spanish, French, German and Portuguese
In the sense unit of astronomical distance:
| Language | Words |
|---|---|
| French | année-lumière |
| German | Lichtjahr |
| Portuguese | ano-luz |
| Spanish | año luz |
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.