This is the 1442nd most frequent Portuguese word.
rei
"Rei" means "king" in English.
The word 'rei' refers to a monarch or king in this context, showing its denotation as a ruler.
O rei governava o reino com justiça.
The king ruled the kingdom with justice.
Here, 'rei' is used metaphorically to denote excellence or being the best in a specific domain.
Ele foi o rei do torneio de xadrez deste ano.
He was the king of this year's chess tournament.
In this sentence, 'rei' is part of a title and still signifies a monarch, reflected in the character's role in the story.