This is the 11339th most frequent Portuguese word.
morder
"To bite."
The word 'morder' here indicates the physical action of biting into an object, attempted by the dog with the ball.
O cachorro tentou morder a bola, mas era muito grande.
The dog tried to bite the ball, but it was very big.
Here, 'morder' is used to describe the act of biting oneself, specifically used as an expression of a habit or reaction while expressing emotional states.
Ela disse que vai morder o lábio se estiver nervosa.
She said she will bite her lip if she is nervous.
The verb 'morder' is metaphorically utilized here to describe the intense sensation of spiciness from the food as if it 'bites.'