In the context of employee-employer relations, the term “grievance” usually relates to an employee’s allegation of a violation of workplace policy or contract terms.
For a unionized workplace, this usually comes up in the context of an employee complaint that the terms of the collective bargaining agreement are not being met. In the context of a nonunionized workplace, a grievance could mean any complaint about noncompliance with work policies or related regulations.
In short, a grievance is a formal employee complaint. Usually this comes about when an employee feels he or she has been negatively affected by the employer not holding up the terms (or misapplying the terms) of the employment agreement. A grievance could come from an individual or a group, and it could relate to a specific contract term or it could be related to violations of the collective bargaining agreement or other employer policies.