Yes. It would help a great deal if Hebrew descendants today had held on to the ע especially. From what we're hearing, ע and א sound the same, pretty much empty. But, ע is supposed to have a big, nasally sound, and be pretty unmistakable. The Arabs still have it, but Hebrew is getting too westernized.
Yan explained above that it refers to the criminal underworld. Think organized crime and such. That wasn't my first thought either. Listening to Hadestown while studying will do that. Speaking of which, anyone who happens to know, is it correct that That underworld would be שאול?
I think that translating underworld to שאול Sheol is not a good idea, because different cultures have different expectations of what goes on in the underworld.
In ancient Jewish thinking, all people went to the underworld, and it was the hope of the righteous that they would be rescued or redeemed someday from Sheol by their God. See Gen. 37:35, Psalm 16:10 and Psalm 89:48.
Later, Greek thinking influenced Hebrew thought so that Hebrews believed that only the wicked go to Tartarus (which Hebrews thought of as Sheol). I can’t can’t find a biblical reference for that last tidbit, but I’m indebted to Dr. Michael S Heiser’s Naked Bible podcast 146 for illuminating this fascinating subject.
It is not a construct state. Like with mobile phone, it's a noun followed by an adjective:
- What kind of phone? A mobile phone
- What kind of world? A lower world (literally)
As a rule of thumb (not a strict rule, but it will give you an idea), you can tell a construct state by putting של between the words to see if it makes grammatical and contextual sense:
- House of books: בית של ספר => בית ספר
- Cake of cheese: עוגה של גבינה => עוגת גבינה
For noun + adjective combinations it doesn't work though:
- World of single underwear (?): עולם של תחתון
- Eh?: טלפון של נייד
This works even in cases where even native Israelis have trouble. For example, יושב ראש = chairman, and many native speakers think it's a construct state, but it's actually just a compound noun. יושב של ראש indeed makes no sense.