- to back sb up
- to support (from the rear)
Generated: This phrase indicates providing support or reinforcement to someone, typically from a position that is not directly involved in the action.
His friends always backed him up during the competition.
Generated: This meaning emphasizes providing assistance or support from a position that is not front-line, often implying a strategic or indirect form of help.
In military operations, the rear troops need to support the front-line soldiers.