Delete or hide a category

Hi,
I added a tag to events. I now want to hide it in timeline and any output. Failing that I would delete the category.
How do I do either? I can’t find anything in help pages.
Thanks!

Are you able to clarify what it is you are looking to hide? Are you just not wanting to display the tag on the timeline (or delete the tag fully), or are you wanting to remove any events that have the tag from the timeline?