What do these referrers mean?

That only means what site they were on before coming to your site. They might be linking to you somewhere on one of their pages, or they just typed in your URL manually when they were looking at that other website first before you.

Well none of the dodgy sites have links to me, and just seems unlikely someone would be on a site selling pills, and then type in my site URL?

This is a very common type of spam – referrer spam. Now that you have posted their links here, the spammers must be even happier ??

Ok… referrer spam? Do please feel free to explain (in non-sarcastic terms) what that means and how it occurs.

https://en.wikipedia.org/wiki/Referer_spam

How have I gone all these years and never heard of that???

Thanks for the link ??

No problem ??