Mazarb · Zigintarâg · Khazaddûmul
'Records [of] Long-beards [= Dwarves] of Khazad-dûm'
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mazarb 'records'; cf. mazarbul 'of records'
Zigintarâg n. 'Long-beards'; it should rather be Sigin-tarâg.  
Khazaddúmul   adj. 'of Dwarrowdelf'


3. Mazarbul Wall Inscriptions.
language of inscriptions: Khuzdul
writing system: Angerthas Moria
author: David Salo
David Salo in Elfling message from November 30, 2002 presented background and meaning of the Moria inscriptions prepared by himself: "In May of 1999, I was asked to provide some translations and renditions into a mode of Angerthas for the runic lettering that would appear on the walls of Moria. I worked with John Howe and Grant Major on this; Grant wrote the texts he wanted rendered into Khuzdul (to be accurate: part Khuzdul, and part my own inventions), and I faxed back transcriptions into cirth. It was a few days' work, and then of course the inscriptions had to be turned into actual artifacts that would give the flavor of the Dwarvish civilization in Moria."
Here are inscriptions in Khuzdul prepared by David Salo. I have tried to find them in the know photos from Mazarbul. The part of inscription seen on the photo is printed in red. Photos with identified runes come from Eris Caffee (Moriel).


Gabil gund Mazarbul Sigin-turgul Khazaddûmul. Durin Uzbad zahra.
'Great Chamber of Records of the Longbeards of Khazad-dûm. Lord Durin built (it).'
All of this is actually attested Khuzdul (though much only in proper names), except for zahra, which is back-formed from -zahar 'building' in Tumunzahar 'Hollowbold', and turgul, which relates to tarâg 'beards', as khuzdul 'of dwarves, dwarvish' relates to khazâd 'dwarves'. Other inscriptions may read (I do not know if all of them were created or not).


Lai Khazaddûm, zibdîn Durin Ulganul
'Behold Khazad-dûm, realm of Durin the Deathless*'
* It seems that the constructors of the gate have transcribed into Angerthas the English text and not its Khuzdul original (!).
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Lai 'Behold' is an invention;  
zibdîn is also an invention, backformed from uzbad, according to the
pattern of khizdîn (in Nulukkhizdîn 'Dwarf-dwelling on the Narog', the old Dwarvish name for Nargothrond).
I forget exactly what the thinking was behind ulganul, but it seems to have the adjectival ending -ul, and probably a privative prefix as well.


Lai Khazad-dûm zai Azanulbizar, Zibdîn Durinônul
'Behold Khazad-dûm by Azanulbizar, realm of Durin's sons'
Durin [certh for 3] Uzbad Khazaddûmu
'Durin III, lord of Khazad-dûm'
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zai 'by, at'; an invented preposition;  
Durinônul: from the invented suffix -ôn "son". 

Durin mabazgûn au Abzag Durinu & [certh for "and"] Náin
Durinul Abzag Durinu ya bazghu
'Durin slain by Durin's Bane, and Náin Durin's son,
Durin's Bane also slew him'
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mabazgûn "slain", from an invented root bazaga with a participial prefix ma- (which I imagined to be seen in mazarbul) and a personal suffix -ûn (cf. the Khuzdul name for Gandalf, Tharkûn "staff-man");  
au 'by (instrumental)': also invented;  
abzag 'bane, slayer': also invented from the same root bazag;  
Durinu: takes -u as the suffix for an objective genitive;  
ya 'also': invented;   
bazghu: past tense form bazg + 3rd singular masculine object suffix -hu.


Thrór Rayad Dáinu; Rakhâs bazghu; Azog wakrish shathûrhu
'Thrór Heir of Dáin; Orcs slew him; Azog cut off his head'
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rayad 'heir' is invented, presumably from a root rayada 'succeed' or the like;
wakrish: from a root karasha 'cut', wa- probably being an adverbial prefix 'off, away';
shathûr is attested in Bundushathûr 'Cloudyhead'; -hu is a 3rd singular masculine possessive suffix.


Frerin Thráinul, Mabazgûn zai Azgâr Azanulbizarul,
zai shakâl Kheled-zâramu & Fundin mabazgûn
'Frerin Thráin's son, slain in the Battle of Azanulbizar,
on the shores of Kheled-zâram, and Fundin slain'
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azgâr: "battle", an invention;
shakâl: "shores", invented, according to the plural pattern of khazâd.

Gabil Azgâr Gundabadul & Ningulul; Mernak Mabazgân
'The great Battle of Gundabad and Gladden; remember the Dead'
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Ningul 'Gladden'; an invention, supposed to resemble Elvish Ninglor;
mernak 'remember', also an invention; I forget the exact reasoning behind this particular form, perhaps meren "remember" plus an imperative suffix, o r a prefix me- (plural?) plus a root ranaka. I suppose it is ironic that I ha ve forgotten the root for remember!


Ganâd Barazinbarul
'(The) mines of Barazinbar'
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ganâd, plural of gund (as in Felak-gundu 'cave-hewer'), on the model of the plural khazâd.