mercaptan
/məˈkapt(ə)n/
"mercaptan" is a 9-letter English headword indexed on PlainSpell.
The verdict
“mercaptan” 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 May 6, 2026) - Any of a class of organic compounds of sulphur, ( R-SH ) where R represents an alkyl or other organic substituent. They tend to be foul-smelling. They are also termed thiols or thioalcohols.
| Property | Value |
|---|---|
| Headword | mercaptan |
| Language | English |
| Part of speech | Noun |
| IPA | /məˈkapt(ə)n/ |
| Letters | 9 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “mercaptan” sits in English frequency
Rare enough to double-check
mercaptan is uncommon English outside the top frequency list, classed as anoun, transcribed /məˈkapt(ə)n/. Rarity is why readers land here mid-draft. Gloss: "Any of a class of organic compounds of sulphur, ( R-SH ) where R represents an alkyl or other organic substituent. They tend to be foul-smelling. They are also termed thiols or thioalcohols.".
mercaptan doesn't appear in our generated misspelling index, and the word's spelling is regular enough that our generator found nothing worth flagging. This headword has no recorded confusable partner, which tends to mean the word is visually distinctive enough to stand on its own.
Etymologically, the entry records: Borrowed from German Mercaptan, from Danish mercaptan; coined by organic chemist William Christopher Zeise in 1832 from mer(curius) (“mercury”) + captan(s) (“capturing”), because the thiolate group bonds very strongly with mercury compounds. The correct English form is mercaptan, spelled M-E-R-C-A-P-T-A-N.
Definition
- 1Any of a class of organic compounds of sulphur, ( R-SH ) where R represents an alkyl or other organic substituent. They tend to be foul-smelling. They are also termed thiols or thioalcohols.
Etymology
Borrowed from German Mercaptan, from Danish mercaptan; coined by organic chemist William Christopher Zeise in 1832 from mer(curius) (“mercury”) + captan(s) (“capturing”), because the thiolate group bonds very strongly with mercury compounds.
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 "mercaptan"?
What does "mercaptan" mean?
How do you pronounce "mercaptan"?
What is the origin of the word "mercaptan"?
Is PlainSpell free to use?
Using “mercaptan”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is M-E-R-C-A-P-T-A-N - every other letter order is a misspelling in standard orthography.
- Say it as /məˈkapt(ə)n/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Browse more English words and confusable pairs in the same reference. English words
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.