melatonin

/ˌmɛləˈtəʊnɪn/

//ˌmɛləˈtəʊnɪn// noun

By · According to Wiktionary data (CC BY-SA) ·

"melatonin" is a 9-letter English headword indexed on PlainSpell.

The verdict

“melatonin” has 13 generated spelling variants in the English index at frequency #30,499. The variants make it a useful spelling check.

#30,499
frequency rank, English
36,575
“M” headwords
13
tracked misspellings
1
confusable pair

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A hormone, related to serotonin, that is secreted by the pineal gland, and stimulates colour change in the skin of reptiles, and is involved in the sleep and wake and reproductive cycles in mammals.

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

melatonin vs melanin
78% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for melatonin
PropertyValue
Headwordmelatonin
LanguageEnglish
Part of speechNoun
IPA/ˌmɛləˈtəʊnɪn/
Letters9
Frequency rank#30,499
Misspellings tracked13
Confusable pairs1
SourceWiktionary (kaikki.org)

Where “melatonin” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). melatonin lands here:

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

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

A misspelling magnet

The generator records 13 spelling variants around melatonin (IPA /ˌmɛləˈtəʊnɪn/), anoun. Corpus frequency is #30,499 among 36,575 “M” headwords. Wiktionary lists 2 senses, so context still picks the gloss.

Our generated misspelling index lists 13 likely wrong-spelling variants for melatonin, with forms such as "emlatonin", "mealtonin", and "melaotnin". Every one of these variants traces to a single-character edit -- an added or dropped letter, a swapped consonant, or a vowel swap -- the kind of slip a spell-checker is built to catch. It also participates in 1 confusable-pair relationship, "melanin", a pairing that trips writers up because the two words share enough sound or shape to blur together.

Etymologically, the entry records: From mela- + tone + -in, ultimately from Ancient Greek μέλας (mélas, “black, dark”). The correct English form is melatonin, spelled M-E-L-A-T-O-N-I-N.

Definition

  1. 1
    A hormone, related to serotonin, that is secreted by the pineal gland, and stimulates colour change in the skin of reptiles, and is involved in the sleep and wake and reproductive cycles in mammals.
  2. 2
    Any material similar in its chemistry and effect to the natural hormone.

Etymology

From mela- + tone + -in, ultimately from Ancient Greek μέλας (mélas, “black, dark”).

This word in other languages

melatonina(Español)mélatonine(Français)Melatonin(Deutsch)

Common misspellings

Also misspelled as:

  • emlatonin
  • mealtonin
  • melaotnin
  • melatnoin
  • melatoinn
  • melatoninn
  • melatonni
  • melatonnin
  • melattonin
  • mellatonin
  • meltaonin
  • mleatonin
  • mmelatonin

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of melatonin - counted as single-character edits (an insertion, a deletion, or a substituted letter). The larger the bar, the easier the typo is to spot; one-edit slips are the ones that sneak past readers.

emlatonin2mealtonin2melaotnin2melatnoin2melatoinn2melatoninn1melatonni2melatonnin1
Edit distance from "melatonin"

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 "melatonin"?
"melatonin" is spelled M-E-L-A-T-O-N-I-N. The IPA pronunciation is /ˌmɛləˈtəʊnɪn/.
What does "melatonin" mean?
As a noun, "melatonin" means: A hormone, related to serotonin, that is secreted by the pineal gland, and stimulates colour change in the skin of reptiles, and is involved in the sleep and wake and reproductive cycles in mammals.
What words are commonly confused with "melatonin"?
"melatonin" is commonly confused with "melanin". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "melatonin"?
The IPA (International Phonetic Alphabet) transcription for "melatonin" is /ˌmɛləˈtəʊnɪn/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "melatonin"?
From mela- + tone + -in, ultimately from Ancient Greek μέλας (mélas, “black, dark”). 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.

Using “melatonin”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is M-E-L-A-T-O-N-I-N - every other letter order is a misspelling in standard orthography.
  • Say it as /ˌmɛləˈtəʊnɪn/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “melanin” - see the side-by-side comparison. melatonin vs melanin
  • Browse more English words and confusable pairs in the same reference. English words

Same frequency band

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.

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

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list