First opened Friday, August 12, 2011
でかい
でかい
- middle-high (nakadaka): falls after mora 2
How to read it: a line over a kana means the voice is high there, and ↓ marks where it drops. A kana with no line is low. With no ↓ the pitch stays high to the end and does not drop even on a following particle (が, は).
huge
Dekai is generally considered a variation of どいかい (doikai), from the emphasizing prefix ど (do-, “very”) plus 厳い (ikai, “great, huge, many”), though one dictionary disputes the sound change.
Taken apart
No breakdown is shown for this word: Wiktionary's text for it doesn't give a split that spells the word and joins to its reading, and any other split would be a guess.
In a sentence
こんなデカイのがチャリの荷台に乗るわけないだろ。
There's no way one that big is going to go on a bike's luggage rest.
あいつでかいことばかり言ってるけど、そのうちぼろを出すよ。
He's always talking like a big shot, but it won't be long before all his faults are exposed.
Sentences are from Tatoeba (CC BY 2.0 FR), picked by fixed rules from a dated export and shown unchanged. Nobody has reviewed them one by one.
What Wiktionary says
Quoted line by line from Wiktionary's Etymology section for this reading, taken from one dated dump so it can't change underneath us. Nothing below is paraphrased.
Not settled
Wiktionary itself hedges on part of this word's origin — those lines are marked below.
- “Found in Hida dialect during the Edo period.”
- “Generally considered to be a variation from どいかい (doikai), from the emphasizing prefix ど (do-, “very”) and the adjective 厳い (ikai, “great, huge, many”). The Nihon Kokugo Daijiten states that the sound change of /doikai/ → /dekai/ does not match the facts of the term's development. However, the /oi/ → /e/ sound shift is quite common in Japanese, and the question may hinge on which form appeared first, でかい (dekai) or でっかい (dekkai). If でかい (dekai) evolved from でっかい (dekkai) instead of the other way around, the do + ikai derivation would not explain the geminate /-kk-/ in でっかい (dekkai). The Nihon Kokugo Daijiten suggests an alternative derivation of でこ (deko, “hugely, enormously”, adverb; old slang or dialect term, persisting in modern でこでこ (dekodeko)) + 厳い (ikai, “great, huge, many”): */deko ikai/ → */dekoikai/ → */dekekai/ → /dekkai/ → /dekai/.”
- Hedged“Also said to be the adjective form of でかし, from いでかす, transitive of 出で来 (ideku, “to appear”). However, the semantic development required for this is improbable, and this is more likely a folk etymology.”
Source: Wiktionary: でかい (dump of 2026-09-02), available under CC BY-SA 4.0. Reading, meaning and part of speech from JMdict, and kanji readings from KANJIDIC2 (EDRDG).
What the labels mean
- 和語 Native Japanese
- Words that were already Japanese before Chinese vocabulary arrived — usually written with kun'yomi and often short.
- Derivation
- A word built from a stem plus a suffix or prefix.
- Sound change
- The pronunciation shifted over the centuries.