ACK
"ack" is a 3-letter English headword indexed on PlainSpell.
The verdict
“ACK” sits in 20 confusable pairs (corpus #33,924) as a verb. The look-alike neighbours are the real trap.
- #33,924
- frequency rank, English
- 3,931
- “A” headwords
- 20
- confusable pairs
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - To acknowledge a packet or a message received from a network.
Corpus desk
Index EN-ack · ACK · English
ACK · rank #33,924 · 0 variants · 20 confusables
- FREQ-MID #33,924
- LEN-MID 3 letters
- VOW-1 1 vowel
- CONFUS-HIGH 20 pairs
- VAR-0 0 variants
- BOOK-MID 3,931
- PHOTO-FINISH acronyms
Nearest frequency peer: acronyms (+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 “ACK”
Peers at similar corpus weight, separate from look-alike pairs below
- 4B
4B
66,080 corpus weight
- ACK
ACK
66,077 corpus weight
- acronyms
acronyms
66,076 corpus weight
- Adderall
Adderall
66,075 corpus weight
- admissible
admissible
66,074 corpus weight
- airlift
airlift
66,073 corpus weight
What this shows Bars place “ACK” against nearest ranked English headwords, not a reprint of the confusable-pair desk.
Visual similarity to commonly confused words
How many letter changes separate each confused pair (Levenshtein distance, normalized).
Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).
| Property | Value |
|---|---|
| Headword | ACK |
| Language | English |
| Part of speech | Verb |
| Letters | 3 |
| Frequency rank | #33,924 |
| Misspellings tracked | 0 |
| Confusable pairs | 20 |
| Source | Wiktionary (kaikki.org) |
Corpus rank beside confusables of “ACK”
Easy to mix with look-alikes
The spelling risk for ACK is neighbouring look-alikes ("as", "at", …), not just typos; it is averb. Frequency #33,924 among 3,931 “A” headwords. Gloss: "To acknowledge a packet or a message received from a network.".
No generated misspelling entries exist for ACK in our index, a sign its spelling follows regular English conventions. It also participates in 20 confusable-pair relationships, "as", "at", "an", and more, a pairing that trips writers up because the two words share enough sound or shape to blur together.
No explicit etymology string is stored for this entry, so its spelling is best explained by sound-to-letter mapping rather than etymology. The correct English form is ACK, spelled A-C-K.
Definition
- 1To acknowledge a packet or a message received from a network.
Recorded use
Wiktionary exampleThese source excerpts show how ACK appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
Yet, with full ECN nonce functionality and totally unreliable behaviour, ACKing individual packets only would require the receiver to maintain state that could theoretically grow without bounds.
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 "ACK"?
What does "ACK" mean?
What words are commonly confused with "ACK"?
What language does "ACK" come from?
Is PlainSpell free to use?
Similar English words by spelling shape
Same letter count and similar misspelling depth for "ACK", not the corpus desk frequency band.
Same letter count
Frequency-ranked English headwords with 3 letters (nearest by frequency rank).