An Italian expression (the use is very common specifically in Rome) that in English means " Your fucking dead relatives". In italian it makes more sense, trust me

Romanesco dialect

1st
It literally means: "your despicable dead relatives".
tua="your", singular

mortacci="despicable dead relatives"
It's used to express strong disapproval of someone (or something that somebody did)

variations :

"mortacci mia"=" my despicable dead relatives"
"mortacci sua"=" his/her despicable dead relatives"
"mortacci vostri"=" your despicable dead relatives", plural

2nd
Sometimes used like an element of surprise

a word that means a person have been so matured

A Tongan boy who is very muscular and strong. Some may refer to him as a horse because of his horse like qualities. He is also a very funny guy.

The umbrella academy is a show that is shit just like Aiden Gallagher

A failed abortion who snipes people's 10 winstreaks in Minecraft bedwars. His parents try to make him feel loved by letting him spend their money on Hypixel.