The word "pathetic" means "not good at all".
Here are a couple of examples of situations in which you can call something "pathetic":
- You were dating a guy, but he cheated on you. Now he's trying to get back together with you by sending messages to a lot of your friends. You don't like him at all, so you call him "pathetic" to your friends.
- You competed in a 10K race. On the day of the competition, you ran a lot slower than you normally do. You're angry at yourself, so you say that your performance in the race was "pathetic".
In general, calling someone else "pathetic" means that you're disgusted by them. Calling yourself "pathetic" means that you're disappointed in yourself.
Calling a product "pathetic" means that it's much worse than it should be.