Marc Adler (of adlerpacific.com), who comments here as marc, sent me a link to Volokh’s post A Pronouncing Dictionary of the Supreme Court of the United States, which begins:
Gene Fidell (Yale Law School) and some of his students are putting together an article tentatively titled A Pronouncing Dictionary of the Supreme Court of the United States, which will basically help people know the standard ways of pronouncing Supreme Court case names (such as City of Boerne v. Flores and Gentile v. State Bar of Nevada). They have a list of cases to include, but if you have some suggestions, please post them in the comments. The requirements, of course, are that (1) it’s not obvious what the standard pronunciation is, and (2) the case comes up often enough to make it worth knowing the standard pronunciation. I should note, of course, that the query isn’t about the right pronunciation in some etymological sense; and even the party’s own pronunciation of his own name may not be relevant in some cases, especially if the case is old enough.
This is an excellent idea, but I can see already, from the comment thread over there, that some people are confused; one says, “My law prof pronounced [Giglio] phonetically (‘JIG-lee-oh’), but under standard Italian pronunciation, the second ‘g’ should be silent” and another says “In the case of getting Giglio correct, probably the most important part is getting it to be two syllables rather than the three that many English speakers would get. So, it’s not jzhee-lee-oh, it’s more like jzhee-lyoe.” Italian pronunciation is of course irrelevant. And it should go without saying that Fidell et al. should not take any one respondent’s word for standard pronunciation.
I was surprised to learn from the thread (and from this Safire column, linked from it) that amicus, in America, is universally pronounced either uh-MEE-kuss or AM-uh-kuss; no one except Justice Stephen Breyer uses my version, uh-MY-kuss, learned (I suppose) from UK-oriented dictionaries like the OED. But (not being a lawyer) I will not change my old mumpsimus for your new sumpsimus.