CDO

noun

"cdo" is a 3-letter English headword indexed on PlainSpell.

The verdict

“CDO” is uncommon English (frequency #55,312 among 43,570 “C” headwords), classed as a noun. The kind of spelling people second-guess.

#55,312
frequency rank, English
43,570
“C” headwords

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Initialism of collateralized debt obligation.

Corpus desk

Index EN-cdo · CDO · English

CDO · rank #55,312 · 0 variants · 0 confusables

  • FREQ-RARE #55,312
  • LEN-MID 3 letters
  • VOW-1 1 vowel
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-DENSE 43,570
  • PHOTO-FINISH CBF

Nearest frequency peer: CBF (-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.

Frequency neighbourhood for “CDO”

Lower corpus rank = more everyday usage (inverted bar length for readability)

corpus weight

What this shows Bars show where “CDO” sits against the nearest ranked English headwords in the FrequencyWords band, not a reprint of letter-browse containment.

Source FrequencyWords open word-frequency list As of May 6, 2026
Key facts for CDO
PropertyValue
HeadwordCDO
LanguageEnglish
Part of speechNoun
Letters3
Frequency rank#55,312
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “CDO” sits in English frequency

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

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

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Rare enough to double-check

CDO is uncommon English at frequency #55,312 among 43,570 “C” headwords, classed as anoun. Rarity is why readers land here mid-draft. 3 senses are on record.

No misspelling variants are generated for CDO in our index, which points to an orthography that plays by predictable English rules. Our dataset records no confusable match here, since nothing in our dataset looks or sounds close enough to cause mix-ups.

No documented word history exists for this headword, so its spelling is easiest explained by how it's pronounced rather than where it came from. The correct English form is CDO, spelled C-D-O.

Definition

  1. 1
    Initialism of collateralized debt obligation.
  2. 2
    Initialism of command duty officer.
  3. 3
    Initialism of chief data officer.

Recorded use

Wiktionary examples

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

  1. The problem is that the connection between subprime default rates, on the one hand, and CDO valuations and default rates, on the other, is so complex that it's very difficult to say in a simple sense that a rise in mortgage defaults will lead to a rise in CDO defaults.
  2. These CDOs had been so sliced and diced that it was possible to claim that a tier of the interest payments from the original borrowers was as dependable as a stream of income on a ten-year US Treasury bond, and therefore worthy of a coveted triple-A rating.

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.

PlainSpell is rendered directly from structured Wiktionary extracts and open word-frequency lists, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 6, 2026. Primary sources: Wiktionary (via kaikki.org) and FrequencyWords.

Frequently Asked Questions

How do you spell "CDO"?
"CDO" is spelled C-D-O.
What does "CDO" mean?
As a noun, "CDO" means: Initialism of collateralized debt obligation.
What language does "CDO" come from?
"CDO" is a English word. PlainSpell covers definitions, pronunciations, and spelling data across English, Spanish, Portuguese, French, and German.
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 "CDO", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 3 letters (nearest by frequency rank).

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