This question arises from my research on Si maritau Rosa, a Sicilian song, where I found what seems to be a clear diminutive of vanedda, that is vanidduzza. Nowhere do I find that word directly, so I have no better guess as to its meaning than assuming it is indeed a diminutive of vanedda and see what the latter means.
And here I find terralab, which gives me "stradina [little road] = vaneddha" – ddh is the way that site denotes the retroflex dd that others (me included… well, I use đđ to be very precise) indicate with plain dd – and salviamoilsiciliano, which explains vanedda as "piccola strada di campagna, o in città, vicolo" (small country road, or, in a city, alleyway). So I come to interpret "apru / a porta a vanidduzza" (which is the part of the song using vanidduzza) as "I open / the door to the small road".
Then I find Sicilian Wiktionary, which gives me a vanedda as "a fessura, socchiuso" (in a slit-like fashion, ajar) in Italian, "entrebâillé, entrouvert" (ajar, half-open) in French, and surprisingly "small street, alley" in English. This gives me a meaning of "slit", with which I interpret "apru / a porta a vanidduzza" as "I half-open the door", which interpretation I prefer, also because of another version of the song giving me "Tegnu la porta aperta / La mettu a padiduzza", which seems to mean "I keep the door open / I put it ajar".
So I wonder: does vanedda have both senses, i.e. mean both "small street" and "slit"? And what sense is used in the song?
I try to go back into the etymology to see how this word formed and maybe choose the option closest to the meaning of its ancestors. I find this blog post which, while discussing the etymology of finestra, mentions vanedda as a possible cognate of vano, itself possibly related (at least semantically) to fanu in Etruscan, which the post says Pittau (never heard that name before…) gives as the ancestor of "finestra" (=window). So vanedda would have formed as a diminutive of vano, originally meaning passage, via addition of -edda, or -ella in Italian (cfr. Grotta delle Vanelle, which I gather is a cave on the Etna volcano in Sicily), so it would mean "small passage" and therefore allow both the above interpretations.
However, when I look vanus (Latin) up on the Wiktionary, besides not finding any such sense (nor do I find it on this dictionary), I find etymological information linking vanus to PIE h₁weh₂-, which means "empty", and does not seem to support that other meaning, and is consistent with the meaning of "vanus", "vain", "empty", "useless".
So where does this word come from? Is it possible that it does come from vanum, which had a semantic shift from "empty(ness)" to "passage", and then to "road" and "slit"? Or is this a bogus etymology? And in the latter case, where does vanedda stem from?
And what does the word mean? Does it have both the meanings suggested above, or only one, and if the latter, which? And if it has both, which one is used in the song?
Edit
«Language-specific grammar and usage questions are off-topic unless primarily concerned with linguistics rather than usage», says the on hold banner on this question. So it appears that the last part of the question, about the meaning of vanedda, is off-topic.
However, I have reason to believe that the etymology part of th question is not off-topic. Alongside the etymology question, the question "How did the meaning of this word evolve in the ages?" should be on-topic.
So let me drop the "current meaning" part, and sum the question up as:
Where does the word "vanedda" come from? Is it possible, as suggested here, that it relates to vano with that word having had the meaning of passage long ago? In that case, would it be correct to say that "vanedda" is vano + -edda, a diminutive suffix, and hence that the meaning evolved from "small passage" into either "narrow road" or "slit"?
