cofferdam

/ˈkɑ.fɚ.dæm/

//ˈkɑ.fɚ.dæm// noun

"cofferdam" is a 9-letter English headword indexed on PlainSpell.

The verdict

“cofferdam” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.

Unranked
below top-frequency English
9
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A temporary watertight enclosure used to create a dry foundation for building bridges and other structures over water.

Corpus desk

Index EN-cofferdam · cofferdam · English

cofferdam · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-LONG 9 letters
  • VOW-3 3 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "C" thin
  • PHOTO-UNK Peer pending

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.

Key facts for cofferdam
PropertyValue
Headwordcofferdam
LanguageEnglish
Part of speechNoun
IPA/ˈkɑ.fɚ.dæm/
Letters9
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “cofferdam” in English

cofferdamranks outside the top 100,000 English headwords, in the long tail of specialist, archaic, or seldom-used vocabulary, exactly the territory where a reader stops mid-sentence to double-check spelling.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

cofferdam is uncommon English outside the top frequency list, classed as anoun, transcribed /ˈkɑ.fɚ.dæm/. Rarity is why readers land here mid-draft. 3 senses are on record.

Zero misspellings are on record for cofferdam in our index, and the word's spelling is regular enough that our generator found nothing worth flagging. It is not paired with a close-neighbour confusable in our dataset, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: From coffer + dam. The correct English form is cofferdam, spelled C-O-F-F-E-R-D-A-M.

Definition

  1. 1
    A temporary watertight enclosure used to create a dry foundation for building bridges and other structures over water.
  2. 2
    An empty space that acts as a protective barrier between two floors or bulkheads on a ship.
  3. 3
    A rubber dam to keep the teeth dry when operating upon them.

Recorded use

Wiktionary examples

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

  1. He stood full six feet in height, with noble shoulders, and a chest like a coffer-dam.
  2. Downstream there was a small wooden cofferdam and when he woke there were naked children splashing in the pool there and he rose and wrapped his jacket about his waist and walked out along the bank where he could sit and watch them.

Etymology

From coffer + dam.

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). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "cofferdam"?
"cofferdam" is spelled C-O-F-F-E-R-D-A-M. The IPA pronunciation is /ˈkɑ.fɚ.dæm/.
What does "cofferdam" mean?
As a noun, "cofferdam" means: A temporary watertight enclosure used to create a dry foundation for building bridges and other structures over water.
How do you pronounce "cofferdam"?
The IPA (International Phonetic Alphabet) transcription for "cofferdam" is /ˈkɑ.fɚ.dæm/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "cofferdam"?
From coffer + dam. 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.

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

Source: FrequencyWords open word-frequency list