What is the meaning of 'smeghead' and in what UK series did the word find the most use and to whom was it said?

The word "smeg" was made up specially for the series "Red Dwarf". It was a swear word which didn't mean anything at all, and could be used without offending anyone. Unfortunately, it is also the name of a Fridge manufacturer, and also looks like the abbreviation of a word which means an unpleasant substance.

Smeg is a vulgarism or expletive used throughout the series of Red Dwarf. Although no specific meaning is ever given, it and its derivatives are regularly used as a derogatory term. On 14 February 2015 at the MCM Midlands Comic Con, Robert Llewellyn explicitly attested that smeg is a shortened version of smegma. The term "Smeghead" is used very commonly throughout as an insult towards characters in the show. It seems to originate from the 1979 Devo film, 'The Men Who Make the Music', where it is used by the character Booji Boy.

https://en.wikipedia.org/wiki/List_of_Red_Dwarf_concepts#Smeg

Lister said it, though I believe Kryton used it on a few occasions.

It is most assuredly a word used here in the states, but you have to be the right kind of a person to A) use it and B) have it used about you. My husband might contest that if you aren't one, you are the other, but I don't really think so.

If you have ever watched the additional footage on the Smeg up videos you will see the acute embarrassment of the cast when asked to explain the word to a young American boy at a Red Dwarf Convention. The word does mean something as it is a shortened version of the word smegma.

I think Lister first calls Rimmer a smeghead in The End. Rimmer duly reports Lister to an officer, Toddhunter. On hearing the report, Toddhunter smiles at Rimmer and puts an arm around him, saying "Oh Rimmer! You ARE a smeghead!". Rimmer explodes and tells Toddhunter that his (Toddhunter's) career is over.

Smoke me a kipper, mo - I'll be back for breakfast.