What does TTL expired in transit mean on a ping attempt?

Related questions

1. Can you find someone's IP?
2. What is the meaning of TTL in ping command?
3. What is the command to trace an IP?
4. What do Traceroute results mean?
5. What are hops in a Traceroute?
6. What is TTL exceeded?
7. What is a TTL value?
8. What is Destination host unreachable?

Tags

1. #computer
2. #forwarding
3. #expired
4. #track
5. #packet
6. #transit
7. #error
8. #particular
9. #number
10. #traffic
11. #routers
12. #pinging
13. #message
14. #crosses
15. #sends
16. #router