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