jIH:

{vIghro'-ghu}

SuStel:

In English, the hyphen used this way represents a genitive relationship

SuStel:

Oh, hunter-killer isn't genitive. That's a different kind of relationship.

Initially, I couldn't understand when a noun-noun construction is to
be interpreted as a genitive relationship, and when as something else.
So I thought of the following:

When a noun-noun construction makes sense if one read it as "noun 2 of
noun 1" then it represents a genitive relationship, but when reading
it as "noun 2 of noun 1" doesn't make sense then it's something else.

So, the {vIghro' ghu} is genitive since it makes sense for it to be
read as "baby of a cat", but the "hunter-killer" is something else
since it makes no sense understanding it as "killer of the hunter".

Would you agree with this approach?

No. The Klingon noun-noun construction is always genitive. When one noun modifies the meaning of another noun, that's genitive. That's true whether you translate it "noun 2 of noun 1" or "noun 1's noun 2" or "noun 2 made of noun 1." What's important is that noun 1 is modifying the meaning of noun 2. That's what makes it a genitive relationship.

The phrase hunter-killer does not contain a genitive. Hunter does not modify killer, and killer does not modify hunter. The entire phrase hunter-killer is used genitively to modify the word probe, but that's not important here. The phrase could also have been written hunter/killer; the hyphen is not important to the meaning here. It's just a shortcut to saying and. The probe hunts and the probe kills. It does both these things, so we're going to stick the two words together a bit sloppily and call it a hunter-killer probe. That's all this means.

vIghro' ghu' is a noun-noun construction, which means they're in a genitive relationship. It's a ghu. What kind of ghu? A vIghro' kind of ghu. It's a Hol. What kind of Hol? A tlhIngan kind of Hol. It's a pegh. What kind of pegh? A nuH kind of pegh. And so on.

-- 
SuStel
http://trimboli.name