protein
/ˈpɹoʊ.tin/noun
protein is spelled P-R-O-T-E-I-N: 7 letters and 2 syllables. It appears 34 times per million words in written English, the 2,831st most frequent word form (wordfreq, 2021 data). As a noun, protein means “Any of numerous large, complex naturally-produced molecules composed of one or more long chains of amino acids, in which the amino acid groups are…” (English Wiktionary, September 2026). The plural of protein is proteins.
How many letters and syllables are in protein?
| Letters | 7: P-R-O-T-E-I-N |
|---|---|
| Syllables | 2 (from its American pronunciation) |
| In writing | 34 times per million words; the 2,831st most frequent word form |
| Wrong spellings searched | none measured in search |
| Pairs people search | |
| Rhymes with | |
| Same letters |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); Bing searches in the United States: the average month from September 2025 to August 2026 (Microsoft Advertising keyword data through DataForSEO, read September 30, 2026); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is protein?
Protein appears 34 times per million words in written English, the 2,831st most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce protein?
- UK /ˈpɹəʊ.ti.ɪn/
- UK /ˈpɹəʊ.tiːn/
- US /ˈpɹoʊ.tin/
Protein has 2 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: En-us-protein.ogg, Wikimedia Commons (author and licence on each file's page).
Words people confuse with protein
Word pairs people search, with the monthly searches for “a vs b” (G: Google, B: Bing, United States).
Sources: Google and Bing searches (September 2025 to August 2026, through DataForSEO); English Wiktionary (homophones, alternative spellings).
What rhymes with protein?
One word on PlainSpell end in the same sounds as protein from its last stressed vowel (/oʊtin/):
Spelled with the same letters in another order: pointer.
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of protein
- proteins plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does protein mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
Any of numerous large, complex naturally-produced molecules composed of one or more long chains of amino acids, in which the amino acid groups are held together by peptide bonds.
- 2
One of three major classes of food or source of food energy (4 kcal/gram) abundant in animal-derived foods (meat) and some vegetables, such as legumes.
- 3
A food rich in protein, often a meat or meat substitute.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Protein in Spanish, French, German and Portuguese
In the sense complex molecule:
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does protein come from?
From proto- + -ein. Suggested by Jöns Jacob Berzelius in a letter to Gerardus Johannes Mulder, from French protéine and German Protein, both coined based on Ancient Greek πρωτεῖος (prōteîos, “primary”), from πρῶτος (prôtos, “first”).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).