Is there a word for a person with only one head?

Reading this article by the fantastic Douglas Adams I came across this interesting quote:

‘[I]nteractivity’ is one of those neologisms that Mr Humphrys likes to dangle between a pair of verbal tweezers, but the reason we suddenly need such a word is that during this century we have for the first time been dominated by non-interactive forms of entertainment: cinema, radio, recorded music and television... We didn’t need a special word for interactivity in the same way that we don’t (yet) need a special word for people with only one head.

This got me thinking — not just about what that word might be (unikef? monocap?), but also how new words are constructed.

My two first thoughts above were that the word would be constructed from either Greek or Latin roots (mono and uni, respectively), and I assume that most newly constructed words would follow a similar structure. That is - they would take previously prescribed pieces of a language (classical or otherwise) and shape those pieces to fit the needs of the new word.

But which language would be more likely? Greek? Or Latin? Or, since the concept of having to describe someone with only one head antedates both of these languages by so much, would it be inappropriate for a new word to have a classical root?

I would appreciate it if any readers who do have multiple heads could let us know authoritatively how you refer to us one-headed folks.

Answer

The point that a word should make is that it has to be an adequate symbol for what it represents.

This is, in essence, arbitrary and pragmatic and what ever work (as a symbol) will make its way into memories and experience of individuals, then a subculture (jargon) and then culture (spreading from common spoken use to use in periodical publications to the moment these words are added to dictionaries).

It can follow patterns from Greek or Latin, and you will find many example in this and last century — we had to invent many new words to deal with advance of information technology.

If you read up on neologism you will find other ways of constructing new words mentioned — combining existing words (regardless of etymology), abbreviating, rhyming, etc..

• 
  

  urban dictionary almost exclusively shows neologisms (even fictional)

  
  


• 
  

  Here you can see new words in journals

  
  


• 
  

  You can also look at lists of words added to a dictionary, such as this sample from Merriam-Webster

  
  

As you examine these lists you will see progression from less adopted words to more standard words and you might see some patterns that make them accepted into the language.

EDIT:

• There is polycephaly - which refers to general condition of having more then one head


• In case of words prefixed with poly-, the usual counterpart is mono- and so your best bet is monocephaly

After I constructed the word, I looked it up and it exists:

mon·o·ce·phal·ic

Bearing one flower head, as in the scape of a dandelion.