**Boundary** — a line or limit that shows where something stops and another thing begins.
Here are some examples of using the word «boundary»:
1. The fence serves as a clear **boundary** between the property and the road.
2. We need to establish **boundaries** with our children to teach them acceptable behavior.
3. The company has strict **boundaries** on the use of personal devices at the workplace.
4. The treaty established new **boundaries** between the two countries.
5. She felt uncomfortable when he crossed the **boundary** of professional discussion and started talking about personal matters.
6. The park has clear **boundaries** to keep visitors away from sensitive areas.
7. He was warned about crossing the **boundaries** of his authority and not to interfere in other departments' work.
8. The coach helped the team set **boundaries** for themselves to improve their performance.
9. The lake is surrounded by a natural **boundary** of hills and trees.
10. The organization's **boundaries** were expanded to include new members from different regions.