sea level

noun

"sea-level" is a 8-letter English headword indexed on PlainSpell.

The verdict

“sea level” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.

Unranked
below top-frequency English
9
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - The nominal height of the surface of the oceans above which heights of geographical features and aircraft flight levels are measured.

Corpus desk

Index EN-sea-level · sea level · English

sea level · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-LONG 9 letters
  • VOW-4 4 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "S" 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.

Key facts for sea level
PropertyValue
Headwordsea level
LanguageEnglish
Part of speechNoun
Letters9
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “sea level” in English

sea levelranks outside the top 100,000 English headwords, in the long tail of specialist, archaic, or seldom-used vocabulary, exactly the territory where a reader stops mid-sentence to double-check spelling.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

sea level is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "The nominal height of the surface of the oceans above which heights of geographical features and aircraft flight levels are measured.".

sea level has no tracked misspelling variants, since its letter sequence doesn't invite the usual edit-distance slips. It is not paired with a close-neighbour confusable in our dataset, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.

This entry carries no recorded etymology, so its spelling is best explained by sound-to-letter mapping rather than etymology. The correct English form is sea level, spelled S-E-A- -L-E-V-E-L.

Definition

  1. 1
    The nominal height of the surface of the oceans above which heights of geographical features and aircraft flight levels are measured.

Recorded use

Wiktionary examples

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

  1. The summit of Everest is 5.5 miles above sea level.
  2. An altimeter is used for measuring height above sea level.

Synonyms

mean sea levelMSL

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.

Frequently Asked Questions

How do you spell "sea level"?
"sea level" is spelled S-E-A- -L-E-V-E-L.
What does "sea level" mean?
As a noun, "sea level" means: The nominal height of the surface of the oceans above which heights of geographical features and aircraft flight levels are measured.
What language does "sea level" come from?
"sea level" is a English word. PlainSpell's reference spans five languages -- English, Spanish, Portuguese, French, and German -- with definitions, pronunciations, and spelling data for each.
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.

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

Source: FrequencyWords open word-frequency list