This is the 9293rd most frequent Spanish word.
acérrimo
"Acérrimo" means "staunch" or "ardent," typically used to describe a strong, unwavering attitude or stance.
Here, 'acérrimo' is used as an adjective to describe someone's intensity or unwavering support towards their ideals.
Él es un acérrimo defensor de los derechos humanos.
He is a staunch defender of human rights.
In this sentence, 'acérrimo' defines the strong and competitive nature of the rivalry.
Mi hermana tiene una acérrima rivalidad con su mejor amiga en los concursos de ajedrez.
My sister has a fierce rivalry with her best friend in chess competitions.
The term 'acérrimo' is employed to emphasize the intensity and unwavering character of the opposition.