ダイヤグラム
だいやぐらむ
noun
diagram; (train) schedule, timetable
1.
diagram; chart (visual representation of data or relationships)
A visual diagram used to illustrate relationships, processes, or data. Used in technical, business, and academic contexts. Often shortened to ダイヤ.
分かりやすいダイヤグラム。
An easy-to-understand diagram.
ダイヤグラムで説明する。
Explain it using a diagram.
会議資料にダイヤグラムを載せてわかりやすくした。
I included a diagram in the meeting materials to make it easier to understand.
2.
(train) schedule; operating timetable
In the context of railways, buses, and other scheduled transport, refers to the operating schedule — the plan of when each train or bus runs. Usually shortened to ダイヤ in this sense, as in 運行ダイヤ (operating schedule) or ダイヤの乱れ (schedule disruption).
電車のダイヤ。
The train schedule.
事故でダイヤが乱れている。
Train service is disrupted due to an accident.
台風の影響で運行ダイヤグラムが大きく変更された。
The operating schedule was significantly changed due to the typhoon.
A loanword from English "diagram" that has taken on two distinct uses in Japanese.
USAGE:
In general contexts, ダイヤグラム refers to any visual diagram or chart — the same meaning as English "diagram." In the world of public transport (especially railways), however, the word has a specialized meaning: the operating schedule itself. This comes from the historical use of graphical time-distance charts to plan train operations. In this transport sense, the word is almost always shortened to ダイヤ.
COMMON COLLOCATIONS:
- ダイヤグラムを描く: to draw a diagram
- ダイヤが乱れる: the train schedule is disrupted
- ダイヤの変更: schedule change
- 運行ダイヤ: operating schedule
- ダイヤ改正: timetable revision (the periodic official schedule update)
SIMILAR WORDS:
- 図: figure, diagram — the native Japanese word, broader and more common for visual figures
- 時刻表: timetable — the printed or posted schedule listing departure times, as opposed to ダイヤ which refers to the operating plan itself
- チャート: chart — often used for business or statistical charts (bar chart, pie chart, etc.)