noun
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
His talk always strays from the main subject.
noun
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.