Root for
Definition 1 of 1
Pro Tip 1/3Informal Use
Commonly used in casual settings, among friends, or in sports and entertainment, not in formal situations. 
We're going to the game to root for our classmates!
Pro Tip 2/3Positive Connotation
Expresses positive feelings and encouragement, showing moral support or hope for success. 
Everyone at the office is rooting for you to win the award.
Pro Tip 3/3Emotional Connection
Often implies a personal or emotional investment in the outcome or in supporting the individual or team. 
She's my sister, so naturally, I'll root for her in the competition.