Decorating a tree is a popular holiday tradition. The crossword solutions for the term DECORATE THE TREE are TRIM, ADORN, and REDO. Trimming a tree involves cutting off any dead or excess branches to give it a neat and tidy appearance. Adorning a tree involves adding decorations such as lights, ornaments, and tinsel to make it look festive. Redoing a tree involves taking down any existing decorations and replacing them with new ones.