How to delete an app that I have already installed?

I want to delete an app that I have installed, but can I delete it so it seams like I never downloaded it in the first place?

Meaning, if i go to purchased on my Iphone, it won't say that it is still somehow connected to my account?

You can't completely remove it but you can hide the purchase.
https://support.apple.com/...u/HT201322
hope this helps