serum
/ˈse.rum/
The verdict
“serum” is uncommon Spanish (frequency #95,721 among 4,169 “S” headwords), classed as a noun. The kind of spelling people second-guess.
- #95,721
- frequency rank, Spanish
- 4,169
- “S” headwords
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Fluido.
Corpus desk
Index ES-serum · serum · Spanish
serum · rank #95,721 · 0 variants · 0 confusables
- FREQ-RARE #95,721
- LEN-MID 5 letters
- VOW-2 2 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-MID 4,169
- PHOTO-FINISH serología
Nearest frequency peer: serología (-2 rank slots)
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.
Rangos de cola larga cerca de “serum”
Banda escasa: las barras invierten el rango para que lo raro se lea más corto
- Sayas
Sayas
4,288 corpus weight
- senza
senza
4,283 corpus weight
- serología
serología
4,282 corpus weight
- serum
serum
4,280 corpus weight
- sexólogo
sexólogo
4,278 corpus weight
- siberianos
siberianos
4,272 corpus weight
What this shows Vista de cola larga: dónde “serum” se sitúa frente a rangos españoles igualmente raros.
| Property | Value |
|---|---|
| Headword | serum |
| Language | Spanish |
| Part of speech | Noun |
| IPA | /ˈse.rum/ |
| Letters | 5 |
| Frequency rank | #95,721 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Cola larga: rango de “serum” en español
Rare enough to double-check
serum is uncommon Spanish at frequency #95,721 among 4,169 “S” headwords, classed as anoun, transcribed /ˈse.rum/. Rarity is why readers land here mid-draft. 2 senses are on record.
serum doesn't appear in our generated misspelling index, suggesting the orthography follows predictable Spanish patterns. This headword has no recorded confusable partner, suggesting its spelling stands apart enough that readers rarely confuse it with something else.
No borrowing history is documented for this entry, so its spelling is easiest to reason about phoneme by phoneme, absent a documented history. The correct Spanish form is serum, spelled S-E-R-U-M.
Definition
- 1Fluido.
- 2Cualquier sustancia acuosa.
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 Spanish corpus, MIT). See the methodology for how each field is sourced and updated.
Frequently Asked Questions
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Similar Spanish words by spelling shape
Same letter count and similar misspelling depth for "serum", not the corpus desk frequency band.
Same letter count
Frequency-ranked Spanish headwords with 5 letters (nearest by frequency rank).