This is the 12273rd most frequent Portuguese word.
rá
"Rá" is an informal exclamation in Portuguese used to express surprise, triumph, or amusement, similar to "aha!" in English.
Here, 'rá' is used as an interjection, expressing surprise or triumph in capturing someone.
Rá! Eu te peguei!
Rá! I got you!
In this sentence, 'rá' appears within the word 'rapidamente', which means 'quickly' and is an adverb derived from the root form 'rápido'.
Ele fez tudo rapidamente, cá para nós.
He did everything quickly, just between us.
In this case, 'rá' is used as an onomatopoeic representation of a sound heard, illustrating how sounds can be described in text.