I see Klingon as a genuine approximation of tlhngan (sp?). I never recognized -on as an ending.
You're close: The word is spelled **tlhIngan**.
The word **ngan** is Klingon for "inhabitant" or "resident", and is found in many demonyms:
tera' = Terra/Earth
tera'ngan = Terran
(Also used is the word
Human.)
romuluS = "Romulus"
romuluSngan = "Romulan
(In
Klingon for the Galactic Traveler, Marc Okrand suggests that this name was adopted from Federation Standard. Presumably because he'd already defined them in
The Klingon Dictionary and later heard that many authors were calling them
Rihannsu.)
nural = "Neural" (the planet)
nuralngan = "Neuralese person"
qarDaS = "Cardassia"
qarDaS wa' = "Cardassia Prime"
qarDaSngan = "Cardassian"
(Cardassia has also been translated as
qarDaSya', and Cardassian as
qarDaSya'ngan. The optional -
ya' ending is common for worlds near, within or beyond Federation space.)
vIraS = "France"
vIraSngan = "Frenchman" or "French person"
vulqan = "Vulcan" (the planet)
vulqangan = "Vulcan" (a person)
(Note that it's
vulqangan, not
vulqanngan (with an additional
n), as one might expect. Perhaps the
n sound has been absorbed into the similar-sounding
ng sound.)
It seems probable that
tlhIngan comes from an old word meaning "resident/inhabitant of Kling". Several of Marc Okrand's works speak of
tlhIng yoS ("the Kling district") on Qo'noS, and other works speak of
a city called Kling.
My own pet theory is that "Klingon" was originally a nationality, rather than a species. Specifically, Kahless' nationality (and perhaps also Molor's). As the Klingon Empire grew and came to encompass all of Qo'noS, all of the planets inhabitants became Klingons, until this nationality became synonymous with the species.
Only a fan theory, but one I rather like.
To get back to writing:
When deciding what an alien race should call another alien race, it's good if one gives some thought to the word's etymology.
For example:
If we are to come up with a Romulan word for "Borg", we should consider:
- Did the Romulans learn of the Borg's existence on their own (living on the border of the Delta Quadrant and all)? Or did they learn of it by eavesdropping on Federation communiques? Or the communiques of some Delta Quadrant species?
- Do we believe that the Borg, by some cosmic coincidence, actually call themselves "Borg", or is it a name chosen with English-speakers in mind?
- Is it perhaps a name that developed during conversations with the El-Aurians, and which the Collective learned of when they assimilated Erin and Magnus Hansen?
Depending on these considerations, the Romulan word for "Borg" may either resemble the word "Borg" very much or very little.
Likewise, if we are then to consider a Klingon word for "Borg", we should ask ourselves: Did the Klingons learn of the Borg through the Federation, through the Romulans, through some other species, or on their own?
Another example is Species 8472, who are also called "the Undine". Depending on how a particular species learned of their existence, they may know them either by their Borg designation, or by some other name.
A real-life (fanon) example:
I have a friend who has written a whole novel completely in Klingon.
Several of the main characters are Orion, but there is no canonical word for "Orion" in Klingon.
She started out calling them
'oraya'ngan, as a phonetic approximation of "Orion" merged with the word
ngan which is discussed above.
However, as we were discussing the lore, we learned that many fans and authors consider "Orion" to be an
exonym (that is, a name for the species that was coined by foreigners, rather than the Orions themselves; similar to how we call Finland "Finland" instead of "Suomi").
The Orions - according to some authors - instead call their home planet Kolar. And, since the Orions were influential traders in the Klingon borderlands (see ENT: "Borderlands"), presumably long before Human-Klingon first contact, it would make sense that the Klingon word for "Orion" should be based on their word for themselves, and not the Federation Standard word for them.
So, she ended up calling the planet qo'lar, and the people qo'larngan.
This is probably much more relevant to language-oriented fans than it is to most authors (who write in English anyway), but I think it's a really nice touch.
I loved the part in the introduction to Diane Duane's My Enemy, My Ally where Ael sits and contemplated the word "Romulan", and wonders why the Humans would use such a strange name for her people.