Deck the Halls with boughs of this?

Answer 1

It means "put a bunch of holly branches all over the walls."

"Deck" means to dress in, as in, "she was decked in satin and diamonds."

"The halls" means, specifically, the hallways and entrance hall of the house, or, large houses often also have a large, high-ceiling room called "the hall" which is used for large parties, dinners and social gatherings.

"Boughs" are leafy branches, and "holly" is a type of plant traditionally associated with Christmas, like mistletoe and pine.

"Tis the season to be jolly": It's the time of the year everyone feels happy.

"Don we now our gay apparel": Let's put on our party clothes.

"Troll the ancient Yuletide Carol": Sing the old-time Christmas songs.

Answer 2

Deck the Halls with Boughs of Holly

Answer 3

Holly