This is the 13938th most frequent Spanish word.
sorprender
"To surprise."
Here, 'sorprender' is used with the meaning 'to surprise (someone)' and indicates causing a pleasant unexpected reaction.
Me gusta sorprender a mis amigos con regalos inesperados.
I like to surprise my friends with unexpected presents.
In this case, 'sorprender' is used to express the idea of an unexpected reaction or astonishment caused by information.
La noticia del descubrimiento científico sorprendió al mundo.
The news of the scientific discovery surprised the world.
Here, 'sorprenderse' (reflexive) refers to one's own experience of surprise or amazement, indicating an internal emotional reaction.