ADU
"adu" is a 3-letter English headword indexed on PlainSpell.
The verdict
“ADU” is an uncommon English word, ranked #63,406 in English word frequency and used as a noun.
- #63,406
- frequency rank, English
- 3
- letters
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Initialism of accessory dwelling unit.
| Property | Value |
|---|---|
| Headword | ADU |
| Language | English |
| Part of speech | Noun |
| Letters | 3 |
| Frequency rank | #63,406 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “ADU” sits in English frequency
Spelling & Dictionary Insight
The English entry for ADU is 3 letters long, classified as a noun. Corpus data places it at rank #63,406 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. The dominant gloss from Wiktionary reads: "Initialism of accessory dwelling unit.".
ADU has no tracked misspelling variants, suggesting the orthography follows predictable English patterns. No close-neighbour confusable shows up for this headword in our dataset, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.
Wiktionary doesn't record an etymology for this headword, so its spelling pattern is best understood through pronunciation rather than a traceable origin. The correct English form is ADU, spelled A-D-U.
Definition
- 1Initialism of accessory dwelling unit.
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
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Using “ADU”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is A-D-U - 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.