This is the 370th most frequent Slovenian word.
uradno
"Uradno" means "officially" in English.
Here, "uradno" is used as an adverb meaning "officially" to describe the state or status of becoming recognized formally.
Končno je postalo uradno: dobil sem novo službo.
It has finally become official: I got a new job.
In this sentence, "uradno" modifies "potrdilo" as an adjective to describe the official nature of the confirmation document.
Ta dokument je uradno potrdilo o tvojem uspehu.
This document is the official confirmation of your success.
Here, "uradno" functions as an adverb to emphasize that the announcement will be made in an official manner.