plaint

noun

1. a complaint.
2. Law. a statement of grievance made to a court for the purpose of asking redress.
3. a lament; lamentation.

noun

1. archaic a complaint or lamentation
2. law a statement in writing of grounds of complaint made to a court of law and asking for redress of the grievance

n.“expression of sorrow,” c.1200, from Old French plainte “lament, lamentation” (12c.), from Latin planctus “lamentation, wailing, beating of the breast,” from past participle stem of plangere “to lament, to strike” (see plague (n.)). Connecting notion probably is beating one’s breast in grief.