Braggadocio is the kind of talking someone does when they are attempting to appear cocky or boastful.
It is also a synonym for braggart, which is the name for a bragger, or someone who is boastful and usually loud about it.
The plural for braggadocio is braggadocios. This is only to be used when referring to two or more people who are braggarts. It should not to be confused with the adjective form, which is braggadocious. Some confusion may come from the adjective form not being recognized by some spellcheckers, so the user would change it to the plural form, unknowingly introducing an error into the text.
Braggadocio may be pronounced with a hard or soft c, which the US preferring the soft and British English preferring the hard.
The word comes from a work of fiction where the character Braggadochio was the personification of bragging.
Examples
When they encounter a checkpoint run by adolescent rebel soldiers, all braggadocio and propaganda, they are terrorised by these boys who delight in their gun-given power. [Financial Times]
The braggadocio was more WWE theatrics than true inflammatory talk, just another Sullivan ritual, part of the giant gathering around this little pocket of stuffed dough. [The Washington Post]
We get a lot of braggadocios in this column claiming they know all about style, but this week, we’ve bagged someone with a bit of creditability on the subject. [Boston Globe]
The braggadocious blend of bold Super Bowl predictions, big personality and brute-force penchant for ground-and-pound offense and aggressive defense made Ryan a hit. [Bleacher Report]