오지다 means satisfying but it is too casual So you better use it with your friends 개 is a slang which means a lot or more You can just take it as the meaning of so good. So you can use it in any situations in which you can say So good :) BUT with your friends :)

Means freaking awesome. For example I can make pasta and ramen and pizza blah blah like a chef and i only learnt about 50 days. Friends = wow that's freaking awesome 개오진다