会議中に話が脱線して、結論が出なかった。
The discussion went off-topic during the meeting, and no conclusion was reached.
あの先生の授業はよく脱線するが、それが面白い。
That teacher's lessons often digress, but that is what makes them interesting.
少し脱線しましたが、本題に戻りましょう。
I got a little sidetracked, but let's return to the main topic.