An operational- or project-level grievance mechanism is a formalized means through which individuals or groups can raise concerns about the impact an enterprise has on them—including, but not exclusively, on their human rights—and can seek remedy.
(Source: United Nations Office of the High Commissioner for Human Rights. 2011. Guiding Principles on Business and Human Rights. http://www.business-humanrights.org/Documents/UNGuidingPrinciples)