Hi,
The sentence below is from a review of the movie Harry Potter and the Order of the Phoenix.
(Dolores Umbridge)Her smile is as tight as her perm; and those little blue Miss Tiggy-Winkle eyes, twinkling as she comes out with yet another line in refined sadism, is enough to make any fourteen-year-old sign up for the revolution.
What does "line" mean in this sentence? There are too many definitions out there. Is it "a remark"?
A 'line' is short for 'a product line'. eg The ABC company produces a line of long-sleeved sweaters.
In your quote, the term 'line' suggests that the woman produces a lot of refined sadism.
btw, "sign up" here means children buy the tickets, and go to see this movie, right? No. It refers to 'revolution.
'Sign up for a class' means 'join a class'. 'Sign up for the revolution' means 'join the revolution (and overthrow this woman)'.
Best wishes, Clive