biofilm

noun

"biofilm" is a 7-letter English headword indexed on PlainSpell.

The verdict

“biofilm” is uncommon English (frequency #54,646 among 4,121 “B” headwords), classed as a noun. The kind of spelling people second-guess.

#54,646
frequency rank, English
4,121
“B” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A thin film of mucus created by and containing a colony of bacteria and other microorganisms.

Corpus desk

Index EN-biofilm · biofilm · English

biofilm · rank #54,646 · 0 variants · 0 confusables

  • FREQ-RARE #54,646
  • LEN-LONG 7 letters
  • VOW-3 3 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-MID 4,121
  • PHOTO-FINISH bifurcation

Nearest frequency peer: bifurcation (-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 “biofilm”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “biofilm” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for biofilm
PropertyValue
Headwordbiofilm
LanguageEnglish
Part of speechNoun
Letters7
Frequency rank#54,646
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “biofilm” in English

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right).biofilmfalls in this rarity band:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Rare peers in the same band: “bifurcation” (#54,645), “besieging” (#54,644), “bluestone” (#54,648). Among 4,121 “B” headwords, “biofilm” is #54,646. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

biofilm is uncommon English at frequency #54,646 among 4,121 “B” headwords, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "A thin film of mucus created by and containing a colony of bacteria and other microorganisms.".

biofilm doesn't appear in our generated misspelling index, since its letter pattern doesn't lend itself to common typo substitutions. This headword has no recorded confusable partner, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: From bio- + film. First used in the early 1970s in the context of wastewater treatment. The correct English form is biofilm, spelled B-I-O-F-I-L-M.

Definition

  1. 1
    A thin film of mucus created by and containing a colony of bacteria and other microorganisms.

Recorded use

Wiktionary examples

These source excerpts show how biofilm appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. The differences in biofilm penetration patterns of both tested photosensitisers and the light source could have played an important role for the survival of microorganisms after the application of aPDT. In a recent own study, we showed that the deepest layers of the oral biofilm were not affected by the aPDT [4 ].
  2. These interactions are essential for the assembly of an exopolysaccharides-rich matrix and the development of cospecies biofilms.

Etymology

From bio- + film. First used in the early 1970s in the context of wastewater treatment.

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

How do you spell "biofilm"?
"biofilm" is spelled B-I-O-F-I-L-M.
What does "biofilm" mean?
As a noun, "biofilm" means: A thin film of mucus created by and containing a colony of bacteria and other microorganisms.
What is the origin of the word "biofilm"?
From bio- + film. First used in the early 1970s in the context of wastewater treatment. See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "biofilm", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 7 letters (nearest by frequency rank).

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list