1. An injury, injustice, or wrong that gives ground for a complaint (a petition for a redress of grievances).
2. The complaint itself ( the client filed a grievance with the state-bar committee).
3. Labor law. A complaint that is filed by an employee or the employee’s union representative and that usu. concerns working conditions, esp. an alleged violation of a collective-bargaining agreement. See grievance arbitration under AR-BITRATION; GRIEVANCE PROCEDURE. [Cases: Labor Relations 411. C.J.S. Labor Relations § 402.]