A term for really big breasts - can be derogatory or complimentary, depending on context. When it is said of a stranger, it tends to be used offensively (generally directed at overweight women); whereas if it is used among friends, it is more commonly an expression of mild jealousy. Guys sometimes would say it to girls who they are hitting on, but the girls don't tend to take it very well. It can also be used by older relatives to embarrass a young teen about their development (awkward)!
"Wow, that lady has a serious case of breasta majesta! Those things could knock out an elephant!"
"My cousin has proper breasta majestas, I'm so jealous..."
"That guy over there told me my boobs were breasta majestas, so I just said he was creepy and walked off."
"Well, aren't you becoming a breasta majesta, just like your dear old Auntie Maud!"