Here are some examples:
* "The candidate was pejoratively labeled as a 'flip-flopper' by his opponents."
* "She pejoratively referred to the outdated technology as 'junk'."
* "The writer pejoratively described the movie as 'a mindless action flick.'"
Essentially, "pejoratively" indicates that the speaker is using language with the intention of putting something or someone down.