Definition of gang up
1 : to make a joint assault ganged up on him and beat him up
2 : to combine for a specific purpose ganged up to raise prices
3 : to exert group pressure ganged up against the boss
First Known Use of gang up
GANG UP Defined for Kids
Definition of gang up for Students
: to join together as a group especially to attack, oppose, or criticize They ganged up on their brother.
Seen and Heard
What made you want to look up gang up? Please tell us where you read or heard it (including the quote, if possible).