fluorescein
"fluorescein" is a 11-letter English headword indexed on PlainSpell.
The verdict
“fluorescein” is uncommon English (frequency #91,513 among 2,507 “F” headwords), classed as a noun. The kind of spelling people second-guess.
- #91,513
- frequency rank, English
- 2,507
- “F” headwords
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Any of a class of yellow xanthene dyes which are visible when highly diluted; used forensically to detect traces of blood, and in analytical chemistry as an indicator in silver nitrate titrations
Corpus desk
Index EN-fluorescein · fluorescein · English
fluorescein · rank #91,513 · 0 variants · 0 confusables
- FREQ-RARE #91,513
- LEN-MEGA 11 letters
- VOW-5 5 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-MID 2,507
- PHOTO-FINISH fluence
Nearest frequency peer: fluence (-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 “fluorescein”
Sparse band: bars invert rank so rarer forms read shorter
- flaying
flaying
8,493 corpus weight
- fleek
fleek
8,492 corpus weight
- fluence
fluence
8,489 corpus weight
- fluorescein
fluorescein
8,488 corpus weight
- Fogerty
Fogerty
8,485 corpus weight
- foretelling
foretelling
8,482 corpus weight
What this shows Long-tail view: where “fluorescein” sits against similarly uncommon English ranks.
| Property | Value |
|---|---|
| Headword | fluorescein |
| Language | English |
| Part of speech | Noun |
| Letters | 11 |
| Frequency rank | #91,513 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “fluorescein” in English
Rare enough to double-check
fluorescein is uncommon English at frequency #91,513 among 2,507 “F” headwords, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "Any of a class of yellow xanthene dyes which are visible when highly diluted; used forensically to detect traces of blood, and in analytical chemistry as an indicator in silver nitrate titrations".
fluorescein has no tracked misspelling variants, typically a sign the spelling maps closely to how the word sounds. Our dataset records no confusable match here, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.
Etymologically, the entry records: From fluoresce + -in. The correct English form is fluorescein, spelled F-L-U-O-R-E-S-C-E-I-N.
Definition
- 1Any of a class of yellow xanthene dyes which are visible when highly diluted; used forensically to detect traces of blood, and in analytical chemistry as an indicator in silver nitrate titrations
Etymology
From fluoresce + -in.
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 "fluorescein", not the corpus desk frequency band.
Same letter count
Frequency-ranked English headwords with 11 letters (nearest by frequency rank).