The location bar drop-down list can show history items, bookmarked pages, pages opened in tabs, and search suggestions. You can set what suggestions show when you enter an URL in the location/address bar bar via Options/Preferences -> Privacy

• Location Bar: When using the location bar, suggest:
  History
  Bookmarks
  Open tabs

You can set this pref to false on the about:config page to disable the location/address bar drop-down list.

• browser.urlbar.autocomplete.enabled = false

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config

Thanks for the suggestion and very interesting references. My problem does not involve autocomplete however, but involves very annoying flashing suggestions for search or use of history which are irrelevant. Normally I do not want any suggestions from the browser and that is the way my browser was set. Using the article I did attempt to modify auto search as well as browser.urlbar suggest history true, and browser .urlbar.suggest bookmarks true. Unfortunately none of these attempts resolved the issue. Hopefully I haven't made it worse.

this problem is not resolved.

Do you mean the search or visit items that appear at the top of the urlbar drop-down list?

Do you want to use autocomplete for the location bar because you can easily disable the drop-down list from opening (browser.urlbar.autocomplete.enabled = false), but it takes more effort to hide these suggestions (code in userChrome.css or Stylish)?