ダイヤ
ダイヤ · daiya · JLPT N3 · noun
agenda
💎🚆 Two English words clipped to daiya: DIAgram (train timetable) and DIAmond
Japanese railways call the timetable chart a diagram, which is shortened to ダイヤ. Diamond (ダイヤモンド) gets cut down to the same sound. So ダイヤが乱れる means the train schedule is disrupted, and ダイヤの指輪 means a diamond ring.