clam up

verb

"clam-up" is a 6-letter English headword indexed on PlainSpell.

The verdict

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

Unranked
below top-frequency English
7
letters

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - To become silent; to stop talking.

Key facts for clam up
PropertyValue
Headwordclam up
LanguageEnglish
Part of speechVerb
Letters7
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “clam up” sits in English frequency

clam up falls outside the top-100,000 ranked English words, the long-tail zone of technical, archaic, or low-frequency vocabulary, exactly where readers second-guess spellings most.

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

Rare enough to double-check

clam up is uncommon English outside the top frequency list, classed as averb. Rarity is why readers land here mid-draft. 2 senses are on record.

clam up doesn't appear in our generated misspelling index, suggesting the orthography follows predictable English patterns. This headword has no recorded confusable partner, since its spelling is unusual enough that it doesn't cluster with a lookalike.

Etymologically, the entry records: By analogy with a clam closing itself. Compare clamshell (“mouth”), clam (“mouth”). The correct English form is clam up, spelled C-L-A-M- -U-P.

Definition

  1. 1
    To become silent; to stop talking.
  2. 2
    To make or become clammy.

Etymology

By analogy with a clam closing itself. Compare clamshell (“mouth”), clam (“mouth”).

Antonyms

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 "clam up"?
"clam up" is spelled C-L-A-M- -U-P.
What does "clam up" mean?
As a verb, "clam up" means: To become silent; to stop talking.
What is the origin of the word "clam up"?
By analogy with a clam closing itself. Compare clamshell (“mouth”), clam (“mouth”). 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.

Using “clam up”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is C-L-A-M- -U-P - every other letter order is a misspelling in standard orthography.
  • Browse more English words and confusable pairs in the same reference. English words
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

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

Source: FrequencyWords open word-frequency list