This is the 489th most frequent Portuguese word.
mim
"Me" (used as an object pronoun).
The word "mim" is used after a preposition "
Este livro foi dado a mim.
This book was given to me.
The word "mim" follows the preposition "para", indicating the recipient of the importance.
Isso é importante para mim.
This is important to me.
"Mim" is used here to indicate the receiver in a context implying personal necessity, following the preposition "para".