heme
/hiːm/
"heme" is a 4-letter English headword indexed on PlainSpell.
The verdict
“heme” is uncommon English (frequency #54,830 among 2,646 “H” headwords), classed as a noun. The kind of spelling people second-guess.
- #54,830
- frequency rank, English
- 2,646
- “H” headwords
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - The component of hemoglobin (and other hemoproteins) responsible for binding oxygen. It consists of an iron ion that binds oxygen and a porphyrin ring that binds the globin molecules; one molecule ...
Corpus desk
Index EN-heme · heme · English
heme · rank #54,830 · 0 variants · 0 confusables
- FREQ-RARE #54,830
- LEN-MID 4 letters
- VOW-2 2 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-MID 2,646
- PHOTO-FINISH Heber
Nearest frequency peer: Heber (-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 “heme”
Sparse band: bars invert rank so rarer forms read shorter
- Hearne
Hearne
45,174 corpus weight
- Heber
Heber
45,172 corpus weight
- heme
heme
45,171 corpus weight
- heng
heng
45,170 corpus weight
- heraldic
heraldic
45,169 corpus weight
- hereto
hereto
45,168 corpus weight
What this shows Long-tail view: where “heme” sits against similarly uncommon English ranks.
| Property | Value |
|---|---|
| Headword | heme |
| Language | English |
| Part of speech | Noun |
| IPA | /hiːm/ |
| Letters | 4 |
| Frequency rank | #54,830 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “heme” in English
Rare enough to double-check
heme is uncommon English at frequency #54,830 among 2,646 “H” headwords, classed as anoun, transcribed /hiːm/. Rarity is why readers land here mid-draft. Gloss: "The component of hemoglobin (and other hemoproteins) responsible for binding oxygen. It consists of an iron ion that binds oxygen and a porphyrin ring that binds the globin molecules; one molecule ...".
No misspelling variants are generated for heme in our index, a straightforward case of a spelling with little room for common typos. We don't track a confusable pairing for this entry, which typically means the spelling is too distinctive to be mistaken for another word.
Etymologically, the entry records: Back-formation from hemoglobin. The correct English form is heme, spelled H-E-M-E.
Definition
- 1The component of hemoglobin (and other hemoproteins) responsible for binding oxygen. It consists of an iron ion that binds oxygen and a porphyrin ring that binds the globin molecules; one molecule binds one molecule of oxygen.
Recorded use
Wiktionary examplesThese source excerpts show how heme appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
The binding of oxygen to the iron molecule causes the hemoglobin molecule to undergo conformational changes that affect the binding of oxygen to other heme sites.
Impossible's breakthrough was in discovering that meat's essence comes from heme—the iron-rich molecule in blood that carries oxygen and is responsible for the deep-red color.
Etymology
Back-formation from hemoglobin.
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); 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
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Similar English words by spelling shape
Same letter count and similar misspelling depth for "heme", not the corpus desk frequency band.
Same letter count
Frequency-ranked English headwords with 4 letters (nearest by frequency rank).