Safari won’t quit
Safari won’t Force Quit. And it is not listed in the Activity Monitor under memory to be force quit there. Now what?
iMac 27", macOS 10.13
Did you sort by name? Did you use the Search function in Activity Monitor.
Once you force quit Safari, relaunch the app holding the Shift key, this is a safe way to relaunch Safari with a problem window or tab re-opening.
http://osxdaily.com/2015/01/18/troubleshoot-safari-freezes-crashes-mac-os-x/
