Topic (noun)

A subject or issue to be discussed, dealt with, or written about.

Origin:

Late middle english (in the sense "place, matter, subject of discussion"): via latin from greek topos "place".

Examples:

1. The topic of climate change was high on the agenda.
2. The topic of discussion was the new policy.
3. We must avoid discussing controversial topics at work.
4. The topic of his thesis was the decline of the Roman Empire.
5. The topic of her book is the history of the world.