This is the 12553rd most frequent Spanish word.
misteriosa
Mysterious.
In this sentence, 'misteriosa' describes the story as being puzzling and intriguing.
La historia que nos contó era verdaderamente misteriosa.
The story she told us was truly mysterious.
The word 'misteriosa' is used as an adjective describing the smile, highlighting its enigmatic or puzzling quality.
La mujer tenía una sonrisa misteriosa que intrigaba a todos.
The woman had a mysterious smile that intrigued everyone.
Here, 'misteriosa' serves as an adjective qualifying the box, implying that it holds secrets or unknown qualities.