All these words came from the same place.

Any guesses? (Answer later)

sitcom
baloney (meaning “nonsense”)
big time
bimbo
bellylaugh
blockbuster
cliffhanger
corny
deejay
demo
disc jockey
dj
emcee
freeloader
hick
hoofer
inside stuff
looker (meaning “beautiful person”)
oldie
palooka
payoff
payola
platter (meaning “a record”)
pushover (of people)
scram
soap opera
vamp
warbler (meaning “singer”)
whodunit

Kudos to Dave Nix for being the first to answer.