Deckthehalls

2 clues
Yuletide tune
Song whose refrain has been prefixed to nine answers in this puzzle
Similar answers:
Dancehalls
Decksthehalls
Deckthehalls
Deckthehals
Deckthemalls
Decktheman
Decktheswab
Defrockthehalls
Firehalls
Inmarblehalls
Lecturehalls