All 6 Uses

theme
in
Book Scavenger
(Edited)

Her parents hadn't realized this was a Halloween-themed concert, and the front benches were filled with zombies, witches, and fairies.
p. 192.2

themed = basic underlying idea
My parents gave it to me as a San Francisco-themed present before we moved here.
p. 201.6
Or here's another idea: Maybe there's an animal theme with the scavenger hunt—gold bug, black cat, Maltese falcon.
p. 208.8 *

theme = recurring idea
Like if she used E for the duplicate symbol: Themed?
p. 242.9

themed = with a basic underlying idea
"You're really good at it," Emily said, thinking of the book-sculpture Bayside Press emblem he'd taken down about a week ago to make his window display Halloween-themed.
p. 257.8

themed = basic underlying idea
Mr. Remora steered a notepad and pencil around a stack of American Revolution-themed novels.
p. 297.6

Definitions:

(1) (theme as in: theme of the novel)
a basic idea that underlies what is being said or done -- especially in a literary or artistic work
(2) (theme as in: musical theme)
the initial or primary melody of a musical composition

or

(as in "theme song") music that is most repeated in a film, television series, or other theatrical production
(3) (theme as in: wrote a 2-page theme on my summer)
an essay written by a student

(This sense of theme is much rarer in recent decades than in the past.)
(4) (meaning too rare to warrant focus)