I remember when I was trying to get a computer job in Japan, I tried to learn some computer terminology worried that I wouldn’t understand any of the technical words in Japanese. Unfortunately, I couldn’t find such a site on the Internet. And so, in an effort to improve the usefulness of the Internet by .00001%, here’s an informative post (hopefully) for the up-and-coming programmers wanting to work in Japan.

General Terminology

オブジェクト指向 (しこう)- Object-oriented
継承 (けいしょう) – inheritance
カプセル化 (か) – encapsulation (black box programming)
抽象クラス(ちゅうしょう) – abstract class
変数 (へんすう) – variable
固定値 (こていち) – constant
値 (あたい) – value
閾値(しきいち) – threshold (often used in validation, program limits, and the like)
関数 (かんすう) – function
メソッド – method (java/c# functions)
引数 (ひきすう) – parameter
戻り値(もどりち) – return value
文字列(もじれつ) – string
配列 (はいれつ) – array
スレッド – thread (no it’s not a sled)
マルチスレッド – multi-threaded
同期(どうき) – synchronous
同期化(どうきか) – synchronize
非同期(ひどうき) – asynchronous
静的(せいてき) – static
動的(どうてき) – dynamic
実行する(じっこうする) – to execute

Design-related Terminology

定義書 (ていぎしょ) – a document that defines something (ex: XML定義書)
クラス図 (ず) – class diagram
基本設計 (きほんせっけい) – basic design (broad level)
詳細設計 (しょうさいせっけい) – specific design
仕様 (しよう) – specifications (what your program is supposed to do)
仕様書 (しようしょ) – written specifications
要件 (ようけん) – requirements
見積もる (みつもる) – to make an estimate
見積もり (みつもり) – estimate

If there are other terms you’re curious about, just let me know and I’ll add it to the list.

19 thoughts on “システム開発における用語

  1. Good suggestions! Most are just Katakana.


    But I’ll add “abstract” and “asynchronous”.

    I’m guessing asynchronous request = 非同期リクエスト

  2. a few more:

    exception: エクセプション or 例外(れいがい)
    structure: 構造(こうぞう)
    source control: ソース管理(かんり)
    bug/defect: バグ/不具合(ふぐあい)
    processing: 処理(しょり)
    initialization: 初期化(しょきか)
    delcaration vs definition: 宣言(せんげn)vs 定義(ていぎ)
    pixel: 画素(がそ)
    character string: 文字列(もじれつ)
    character set: 文字集合(もじしゅうごう)

  3. Those are some good ones especially 初期化.

    Other good words are 運用 and インフラ. Maybe I’ll add them.
    Stuff like 夜間処理バッチ goes under 運用.

  4. What about verbs? Like:
    * calling a function/method
    * returning from a function
    * passing back a value
    * assigning a value to a variable
    * comparing two values

  5. メソッドを呼び出す = call method
    戻り値 = return value
    渡す = to pass

    My memory is definitely getting rusty…

  6. Hi. Great blog, been reading for years. (well, through 3yen)

    This is probably something you already know, but just in case you don’t…

    I reacently bought myself a Canon V90 電子辞書 which is meant for japanese people learning chinese, but it obviosly have english to japanese and chinese as well. Anyway, the important function for this thread is that it have a Jpn Chn Personal Computing dictionary. You can do searches from Japanese, English, Pinyin and kanji. The best thing with it, from a japanese standpoint, is that you get the search results in english, chinese and japanese. So for this very subject it would be a good device. I’m sure others have it as well, but this is the only one I’ve owned who has had a specific PC dic so I can only speak for this brand and version. Bought it here in japan for a little above 22万円 because I’m also contemplating adding chinese to my list of languages, and I’m currently studying japanese full time here. It’s not exactly the cheapest jap-eng-chn dictionary but I chose this one because it has recorded pronounciations for the chinese, and I’m slow starting and thought I’d start tackling spoken chinese first and take it slow with the kanji in the beginning. I feel I’m still struggling with kanji in japanese, so going too deep into written chinese feels a bit too daunting for me right now.
    Anyway, since you are learning Chinese as well, it might be an interesting device.

    But as I said at the beginning… This is probably something you’ve already contemplated and or have already.

  7. Hi Tipster,

    Thanks for the tip. Yes, I already have a Canon G90 and it works great though the screen is a little dark. I chose the G90 over V90 because of 中日大辞典 which has the most entries for Chinese. Personally, I think the recorded pronunciations are overrated for Chinese. The sound quality isn’t very good and useless once you learn proper pinyin pronunciation. Of course, for English it’s invaluable since it’s not phonetic.

    It looks like they have a newer model (G903) now that has practically everything. I probably would have gotten that if it was out when I purchased mine.


    I only wish they would add a backlight or something for the dark screen.

  8. I was actually thinking of buying the G903. It’s not all that much more expensive. Just around 1万円 more, but considering what you get, that’s not that much. But as I was perusing I got stingy for some reason.

    Oh, and a correction. When I wrote 22万円 in my previous post, I obviosly meant 2万円. I dubbletap my keys by mistake sometimes.

    You’re probably right about the recordings. I haven’t learned pinyin yet though. I’m in the proccess of learning though.

    Another unexpected “problem” in my case is that my friends is mostly taiwanese people. I knew that the taiwanese pronounciation is a bit different than native chinese, it turns out that eventhough they speak mandarin, they sometimes use/choose different words than a native chinese would. Which has led to me choosing the “wrong” word from my dictionary when trying to speak to them. Not the dictionarys fault obviosly, just an observation.

    Guess I have to try and spend more time with my native chinese friends as well.

  9. Even though there are small differences between the Chinese spoken in Taiwan vs elsewhere, that’s really unavoidable. You’ll see the same thing with Northern Chinese, Southern Chinese, Shanghai, etc. Though considered “standard”, even Beijing dialect has distinct characteristic. Personally, if I was at the level that I had to worry about that, I’d be really happy.

    I think the bigger problem you might not have realized with Taiwanese is that they still use traditional Chinese while the Canon dictionaries are simplified. If you want to look up compounds in traditional on the Canon, you’ll have to look up each individual character first to find the simplified equivalent and then look up the compound with the simplified version. It’s a pain which is why I prefer to just stick to simplified. Unfortunately, most of the literature in my local library/book store are in traditional. Sigh…

  10. A few that I learned working with web sites:

    機能(きのう) – feature/function
    本番(ほんばん) – production
    本番化する(ほんばんかする) – productionise (go live)
    言語(げんご) – language (it’s also used for ‘programming language’)
    ほげほげ – Japanese for ‘foobar’

  11. Those are some good suggestions, I’ll have to add them to the list.

    There’s also テスト環境 vs 本番環境.

  12. What a great resource! I was talking about this very same topic with my language exchange partner a few weeks ago. Here’s some of the terms I wrote down from our conversation:

    修正する (しゅうせいする)revise
    先祖がえり(せんぞがえり)degrade, degradation
    “Create a class that will call the service methods of ABC API and return an array.” = ABC API をつかってarrayを作り出すクラスを作る。
    値を出す (あたいをだす)output the number
    集約する(しゅうやくする)gathering requirement
    見積もる(みつもる)estimate (time)
    情報工学系 (じょうほうこうがく) computer science

  13. There is this dictionary section on Yahoo that might be useful:


    One thing I did to learn programming terminology was use wikipedia. I did some combination of look up the term in English and switch to Japanese, or browse around the Japanese and switch back to English if I need to.

    Anyway, here are some other random suggestions:

    データ型 (データがた) data type
    入力 (にゅうりょく) input
    出力 (しゅつりょく) output

    参照 (さんしょう) reference
    返値 (かえりち return value (alternative to 戻り値)

    日本語版 (にほんごばん) Japanese language version
    設定 (せってい) setting

    変更 (へんこう) modification
    追加 (ついか) addition

    I work in embedded software and lots of the terminology I know may not be so useful to general application developers. For example:

    割り込み (わりこみ) interrupt
    仮想 (かそう) virtual (as in virtual memory)
    移植 (いしょく) porting

  14. Thought I’d update this with some of the vocab that I’ve picked up since I started working:

    指定 してい assignment
    不具合 ふぐあい defect
    修正 しゅうせい correction;
    進捗 しんちょく progress
    挿入 そうにゅう insertion
    済み すみ completed;
    taken care of
    完了 かんりょう completion
    見込 みこむ to estimate;
    to anticipate
    抜け ぬける to be omitted;
    to be missing
    見通し みとおし forcast;
    権限 けんげん (access) permissions;
    終了 しゅうりょう end
    ; termination
    出力 しゅつりょく output
    向上 こうじょう improvement
    測定 そくてい measurement
    数 かず amout
    ; number
    比較 ひかく comparison
    連携 れんけい coordinated;
    計測 けいそく measurement
    表 ひょう table
    行 ぎょう row
    構造 こうぞう structure
    ; architecture
    設定 せってい configuration
    ; setup
    実施 じっし implementation
    ; carry out
    複合 ふくごう combined;
    頻繁 ひんぱん frequent
    検討 けんとう study
    ; examination
    実装 じっそう implementation
    保守 ほしゅ maintenance
    資料 しりょう documents
    作成する さくせいする to create
    対応 たいおう deal with
    ; address;
    要求 ようきゅう request
    ; demand
    洗い出し あらいだし elimination
    予測 よそく estimation
    条件 じょうけん requirements;
    ; conditions
    順次 じゅんじ sequential
    転送する てんそうする to transfer (files)
    直接 ちょくせつ directly
    算出する さんしゅつする to calculate
    投入 とうにゅう input;
    実行する じっこうする to execute
    環境 かんきょう environment
    接続 せつぞく connection
    切断 せつだん disconnection
    再構築 さいこうちく rebuilding
    作業 さぎょう work;
    箇所 かしょ point;
    並列処理 へいれつしょり paralell processing
    圧縮 あっしゅく compressed;
    解凍 かいとう uncompressed
    ; unzipped
    定義する ていぎする to define
    取得する しゅとくする obtain
    容量 ようりょう capacity
    物理 ぶつり physical (memory)
    書き込み 書き込み write (access)
    表示 ひょうじ indicator

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