MSL

noun

"msl" is a 3-letter English headword indexed on PlainSpell.

The verdict

“MSL” is uncommon English (frequency #54,953 among 4,057 “M” headwords), classed as a noun. The kind of spelling people second-guess.

#54,953
frequency rank, English
4,057
“M” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Initialism of mean sea level.

Corpus desk

Index EN-msl · MSL · English

MSL · rank #54,953 · 0 variants · 0 confusables

  • FREQ-RARE #54,953
  • LEN-MID 3 letters
  • VOW-0 0 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 4,057
  • PHOTO-FINISH mtDNA

Nearest frequency peer: mtDNA (+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.

Long-tail ranks near “MSL”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “MSL” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for MSL
PropertyValue
HeadwordMSL
LanguageEnglish
Part of speechNoun
Letters3
Frequency rank#54,953
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “MSL” in English

This scale runs from the tiny cluster of words that carry ordinary speech (left) to the long tail of words almost nobody reaches for (right).MSLfalls in this rarity band:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Rare peers in the same band: “mtDNA” (#54,954), “mugger” (#54,955), “mui” (#54,956). Among 4,057 “M” headwords, “MSL” is #54,953. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

MSL is uncommon English at frequency #54,953 among 4,057 “M” headwords, classed as anoun. Rarity is why readers land here mid-draft. 2 senses are on record.

No misspelling variants are generated for MSL in our index, a sign its spelling follows regular English conventions. No confusable counterpart is on file for this word, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: Abbreviation. The correct English form is MSL, spelled M-S-L.

Definition

  1. 1
    Initialism of mean sea level.
  2. 2
    Initialism of maritime/marine security, large; a type of cutter or (sovereignty, freedom-of-navigation, surveillance/reconnaissance) patrol vessel/craft/boat/ship.

Recorded use

Wiktionary example

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

  1. The company shard specific data from today’s flight on social media, revealing that the New Shepard capsule that carried Katy Perry, Gayle King and their crewmates to space hit 346,802 feet above ground level (AGL) and 350,449 above mean sea level (MSL).

Etymology

Abbreviation.

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 "MSL"?
"MSL" is spelled M-S-L.
What does "MSL" mean?
As a noun, "MSL" means: Initialism of mean sea level.
What is the origin of the word "MSL"?
Abbreviation. See the full etymology section above for more details.
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 "MSL", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 3 letters (nearest by frequency rank).

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

Source: FrequencyWords open word-frequency list