Trimming the tree

This past christmas I heard someone use the phrase 'trimming the tree.' I was surprised I haven't heard that phrase before, so I asked them what they meant - and they said this meant decorating the tree for christmas.
According to the Merriam-Webster Dictionary the word 'trim' means to 'embellish with ribbons, lace and/or ornaments' as well as 'to cut', or 'to beat.' Initially when they said they were trimming the tree, I thought they were giving the tree a hair cut lol because to me that's what trim means but in fact trimming in this context also means to decorate, to embellish. The phrase could also be reworded as 'trimming the house', which would basically mean to embellish the house with christmas lol or something like that. I'm sure I'm not the only English Yankee who had to take a second look at this. So, next year I guess I'll be joining the rest of you in trimming my house and tree...