How many meanings does this word have?
Some Italian speakers also use it as an alternate to suono, meaning "sound."
This is either found in archaic Italian (since the word sprang from Latin sonus ), or in varieties of the spoken language tinged with local dialects (regional Italian) in which the archaic form of the word has lingered.
In modern Italian, the third person plural is not typically used for the formal you plural, unlike in Spanish, for example. The third person singular (Lei) is used for the formal you singular, but the plural is almost always "voi," regardless of whether it is in a formal or informal context.
Yeah, I think most usages of Loro for "you" that I've seen have been in novels or short stories written in the mid 20th Century or earlier. Alberto Moravia used it a lot, but he also liked to use pronouns like egli and ella that I don't think I've ever heard a present-day Italian person use :)
In formal contexts, Loro for a plural "you" is still used, albeit rather seldom.
A learner will barely ever happen to hear the Loro scheme in everyday's conversation but, for instance, the staff of a posh restaurant, or the concierge of a five-star hotel should always address guests using the Loro scheme.
The expression Lor Signori (sometimes spelt Lorsignori) was commonly used instead of saying simply Loro, which at a formal level may sound too abrupt.
Nowadays this scheme has become more and more infrequent, following a general decline of formal manners.
But in some cases Lor Signori is used in a humorous way, for addressing or greeting friends in an overly formal tone.