You can go to your History listing and manually remove those history not needed. You can't remove url "BankName" that is site locked and only the user History is the only thing you can delete.

Thanks for replying so promptly I didn't want to advertise the actual name of my bank so I guess I confused the question. Let me give an example. The old URL of my bank started "bankname-online"; the new URL starts "online-bankname". When I type "bankname" into an empty address bar I get a drop-down list of lots of old URLs and I have to grind through to find the new one or at least try to remember it. I just want to delete all those old URLs without have to step through one by one. It would be so simple if there were a delete option of everything that starts with ... whatever i.e. I could type in bankname-online and delete all the URLs that start with that while preserving everything else, all with one click.

Why don't you type bankname-online (or -online) in the search bar in the Library/sidebar to see what comes up ? You can use Ctrl+A and Delete to remove selected entries, possibly uncheck items via a Ctrl + left-click.

Great. The Library search enabled the granularity I needed to filter only the numeerous bankname URLs I wanted to delete, leaving the ones I want to keep. Many thanks to you and the rest of the Mozilla community