decidable
[dɪˈsaɪdəbəɫ]
"decidable" is a 9-letter English headword indexed on PlainSpell.
The verdict
“decidable” is uncommon English (outside the top frequency list), classed as an adjective. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 9
- letters
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - capable of being decided.
Corpus desk
Index EN-decidable · decidable · English
decidable · unranked · 0 variants · 0 confusables
- FREQ-UNRANKED Unranked
- LEN-LONG 9 letters
- VOW-4 4 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-THIN "D" thin
- PHOTO-UNK Peer pending
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.
| Property | Value |
|---|---|
| Headword | decidable |
| Language | English |
| Part of speech | Adjective |
| IPA | [dɪˈsaɪdəbəɫ] |
| Letters | 9 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “decidable” in English
Rare enough to double-check
decidable is uncommon English outside the top frequency list, classed as anadjective, transcribed [dɪˈsaɪdəbəɫ]. Rarity is why readers land here mid-draft. 3 senses are on record.
decidable doesn't appear in our generated misspelling index, a sign its spelling follows regular English conventions. We don't track a confusable pairing for this entry, which typically means the spelling is too distinctive to be mistaken for another word.
Etymologically, the entry records: From decide + -able. The correct English form is decidable, spelled D-E-C-I-D-A-B-L-E.
Definition
- 1capable of being decided.
- 2describing a set for which there exists an algorithm that will determine whether any element is or is not within the set in a finite amount of time.
- 3in intuitionistic logic, a proposition P is decidable in a given theory if it can be proven from the theory that "either P or not P", i.e. in symbols: P∨¬P.
Recorded use
Wiktionary exampleThese source excerpts show how decidable appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
It is easy to show that the set of even numbers is decidable by creating the relevant Turing machine.
Etymology
From decide + -able.
Synonyms
Antonyms
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.