ICD

noun

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

The verdict

“ICD” sits in 20 confusable pairs (corpus #34,926) as a noun. The look-alike neighbours are the real trap.

#34,926
frequency rank, English
2,140
“I” headwords
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Initialism of implantable cardioverter-defibrillator.

Corpus desk

Index EN-icd · ICD · English

ICD · rank #34,926 · 0 variants · 20 confusables

  • FREQ-MID #34,926
  • LEN-MID 3 letters
  • VOW-1 1 vowel
  • CONFUS-HIGH 20 pairs
  • VAR-0 0 variants
  • BOOK-MID 2,140
  • PHOTO-FINISH Ilya

Nearest frequency peer: Ilya (+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 neighbours of confusable “ICD”

Peers at similar corpus weight, separate from look-alike pairs below

corpus weight

What this shows Bars place “ICD” against nearest ranked English headwords, not a reprint of the confusable-pair desk.

Source FrequencyWords open word-frequency list As of September 3, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

ICD vs in
0% similar
ICD vs is
0% similar
ICD vs it
0% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for ICD
PropertyValue
HeadwordICD
LanguageEnglish
Part of speechNoun
Letters3
Frequency rank#34,926
Misspellings tracked0
Confusable pairs20
SourceWiktionary (kaikki.org)

Corpus rank beside confusables of “ICD”

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

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

Ticks step logarithmically, so each one marks a roughly tenfold drop in how often the word turns up. Same rarity band neighbours include “Ilya” (#34,927), “humping” (#34,924), “immeasurable” (#34,928). Among 2,140 “I” headwords, “ICD” is #34,926. Source: FrequencyWords open word-frequency list.

Easy to mix with look-alikes

The spelling risk for ICD is neighbouring look-alikes ("in", "is", …), not just typos; it is anoun. Frequency #34,926 among 2,140 “I” headwords. Gloss: "Initialism of implantable cardioverter-defibrillator.".

ICD doesn't appear in our generated misspelling index, typically a sign the spelling maps closely to how the word sounds. It also participates in 20 confusable-pair relationships, "in", "is", "it", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.

This entry carries no recorded etymology, so its spelling is best read as a straightforward mapping from sound to letter. The correct English form is ICD, spelled I-C-D.

Definition

  1. 1
    Initialism of implantable cardioverter-defibrillator.

Recorded use

Wiktionary examples

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

  1. Both CRT-Ds and ICDs are implanted under the skin, in the patient’s upper chest area. The devices have wires called leads that attach to the heart and regulate the rhythm of the muscle. Defibrillators help patients with bradycardia – a slow heartbeat – by pacing the heartbeat and those with tachycardia – a fast heartbeat – by delivering shocks that reset…
  2. Serie A club Inter Milan – whom Eriksen had been contracted to at the time of the incident – let the midfielder move abroad as he was unable to play in Italy unless the ICD device was removed.

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 "ICD"?
"ICD" is spelled I-C-D.
What does "ICD" mean?
As a noun, "ICD" means: Initialism of implantable cardioverter-defibrillator.
What words are commonly confused with "ICD"?
"ICD" is commonly confused with "in", "is", "it". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
What language does "ICD" come from?
"ICD" 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 "ICD", not the corpus desk frequency band.

Same letter count

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

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

Source: FrequencyWords open word-frequency list