main topic; main subject; main issue; main question
Refers to the central theme or point of a discussion, meeting, or piece of writing. Often used when moving from preliminaries to the core matter.
前置きはこれくらいにして、本題に入りましょう。
Let's stop the preliminaries and get to the main topic.
彼の話はいつも本題からそれてしまう。
His talk always strays from the main subject.
this subject; the matter at hand
Used to refer back to the current topic under discussion, often in formal or written contexts. Less common than sense 1.
本題について、もう少し詳しく説明してください。
Please explain this subject in a little more detail.
The conversation strayed from the main topic.
Let's get back to the main topic now.
He nervously brought up the main topic.