It is a long-standing doctrine in Etruscan studies that the Italic title maro (pl. marones) has a counterpart in the Etruscan language as maru, a term assumed to be related through borrowing. Massimo Pallottino lists the following entry in the vocabulary section found at the end of his book The Etruscans (1975):
maru title of magistracy (= Lat. maro, Umbrian maron-); connected and derived forms: marnu, marniu, marunu, marunuχ, maruχva, marunuχva: zilaθ maruχva, zilc marunuχva, marunuχva cepen, etc. titles; maru- (marv-as) verb denoting the exercise of the magistracy.
Any critiques on the work of Etruscologists are hard to come by, yet there are many valid reasons to question this and many other sacrosanct translations based on linguistical grounds.
For one thing, and the most grammatically obvious, the word marunuχ sometimes sports the suffix -va, which is precisely what we would expect for an inanimate noun! The suffix -va is a known allomorph of -χva that is used after stems ending in certain consonants (eg: PyrT 1.i-ii heramaśva 'idols'; see Etruscan grammar [pdf] by Micheal Weiss of Cornell University).
Another important oddity of this word is never explained by either Pallottino or any of his academic followers to date: Why do we find so many alternate forms *all* translated the same way, such as maru, marnu, marniu, maruχva, marunuχ or marunuχva?! Indeed, they are all in exactly the same funerary contexts, but what then is the grammatical difference between the stem maru- and the stem maru-nu-? If it were honestly expressing a position of power, the Etruscans would surely have agreed upon a single term. If Etruscologists were speaking from a position other than ignorance, they would have been able decades ago to adequately explain what -n(i)u- adds to the meaning of this word. They have yet to do so.
When we realize how misguided the translation of this word is, we may then start to notice a larger, ominous pattern that becomes evident in Massimo Pallottino's work on the language: the overindulgence in ad hoc Latin-Etruscan comparisons. Have you been fooled too?
The only way to sift through this paleoglottal tomfoolery is to always, always, always look at these words in their proper context, in their original inscriptions. Never let an author pull the wool over your eyes. Go straight to the source and question:
TLE 133: Marunuχva cepen tenu, zilaχnu.
TLE 170: Zilc marunuχva tenθas.
TLE 190: Maru Paχaθuras Caθs-c, lupu.
CII 2070: Marunuχ spurana cepen tenu.
If we are to understand what maru(-nu)- really is, we need to take note of the patterns in the inscriptions. As I explained above, Etruscan grammar itself is telling us that this word expresses a countable, inanimate object, not a person.
We see further that there is a verb that operates on this object: ten. This verb too has been the victim of Pallottino's ad hoc Latin-tainted whims since he mistranslates it as "'to act' in the sense of 'to exercise a magistracy'" (The Etruscans, p.232), a clear connection to Latin tenēre 'to hold' (in this case, 'to hold a position') even though he doesn't explicitly admit this in his book. Knowledgeable experts nowdays agree that Etruscan is entirely unrelated to Latin so these impulsive connections just get in our way of properly understanding this language.
In both TLE 133 and CII 2070, the verb is in the passive (-u) and thus it informs us that the "marunu" objects are being "ten"-ed. In TLE 170, it is the subject zilc that is "ten"-ing the "marunu" objects but yet again, the same action is being performed on them. If the maru in TLE 190 is at all expressing the same object as *marunu (an iffy proposition that needs to be demonstrated both by its context and by a detailed explanation of its morphological elements), we should note that the sentence conveys that the object belongs to both Paχaθur (ie. "those of Bacchus") and Caθ (apparently a deity that we also find inscribed on the bronze Piacenza Liver artifact).
Given the above data, I hardly think any reasonable and informed scholar can possibly take Pallottino's translation of maru seriously any longer.