How to say "redundancy" in Japanese
Choosing the right word
- 重複ちょうふくsuru verb, intransitive verb, no-adjectiveThe most common choice: covers duplication, repetition, or overlapping content. Use it when something is stated or included more than once, in everyday and technical contexts alike.
- 蛇足だそくno-adjectiveRefers to a useless addition — something tacked on that serves no purpose, such as needless extra remarks in writing or speech. It suggests the addition detracts rather than merely repeats.
- nounA loanword used mainly in technical fields such as computing and engineering, where system redundancy (backup components, fail-safes) is meant. Outside such contexts it is seldom the word you want.
- 冗長性じょうちょうせいnounThe usual technical term for redundancy as a property, especially in computing and engineering — the built-in duplication that keeps a system working if part of it fails.
- 冗長度じょうちょうどnounA technical term for redundancy specifically in information theory — the degree to which a message or code contains more symbols than strictly necessary. Uncommon outside that field.
Use 重複 for overlap or duplication in general contexts, 冗長性 or 「リダンダンシー」 for technical redundancy (engineering, computing), 冗長度 for information theory, and 蛇足 for a useless addition to writing or speech.
Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only
Japanese equivalents
