Definition of "pronunciamento"

I think of Spengler and of his terrible pronunciamentos, and I wonder if style, style in the grand manner, is done for.

1934, Henry Miller, Tropic of Cancer, Grove Press, published 1961, page 6

After assembling an army in Catalonia, he marched on Madrid, issuing en route a pronunciamento calling on the Queen Regent to banish Valenzuela and to accept him as her first minister.

2007, Tim Blanning, The Pursuit of Glory, Penguin, published 2008, page 249

[H]e did not want to see Brazil suffer the same fate as those South American countries whose history has been nothing but a succession of barrack-room pronunciamentos.

1984, Mario Vargas Llosa, translated by Helen R. Lane, The War of the End of the World, Folio Society, published 2012, page 156