How do I kill "SQL Developer" that seem to be in deadlock using ps aux and kill -9? I have SQL Developer from Oracle installed. It seems to be frozen at the moment and I can't force quit it.

I can't open it because of this and hence can't use it too

I don't want to shut down my Mac every time so I want to kill it using kill -9 but I don't know its name nor pid so I'm clueless.

How do I kill it?
If you can't find it by running ps aux or pgrep -i developer you can run Activity Monitor to get the PID of the process (and also to kill it directly).