I was just testing out how to delete custom fields in Wrike and I discovered there's not an obvious intuitive way to do this.
This was really frustrating before I found the solution because I thought I'd just have to either hide it (which felt like sweeping dirt under a rug) or rename it.
Luckily, there is in fact a way to delete custom fields in Wrike without having to find work arounds. 🙂
All you need to do is go all the way to the left of the Table view of your Folder/Project/Task (whichever/wherever you're wanting to remove the custom field), and you'll see a gear icon at the top left corner.
At the bottom you'll see the the custom fields you created.
Beneath there, you'll see a button that says "Manage Custom Fields". Click on it.
In that menu, you'll see the custom fields you created. Just right click on the custom field you created and click the "Remove" button. And BOOM! Your annoying custom field you couldn't remove is gone :)
If you experience any issues with removing it from everything, just find the folder/project the custom filed is stuck to and you'll be able to get rid of it from there, but it should just go away if you clear it from the parent folder.
Hope this helps!