Root for is an expression used to show support for someone or something. The crossword solutions for this term are CHEER (5 letters), URGEON (6 letters), and CHEERON (7 letters). CHEER is a verb meaning to shout words of encouragement, while URGEON is a noun meaning one who encourages or cheers on. CHEERON is a combination of the two words, and can be used as either a verb or a noun. All three words can be used to express support for someone or something.