An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

To express dissatisfaction, pain, uneasiness, censure, resentment, or grief; find fault (Dictionary.com).

M.E. compleinen, from O.Fr. complaindre "to lament" from V.L. *complangere, originally "to beat the breast," from L. → com- an intensive prefix + plangere "to strike, beat the breast."

Mid.Pers. garz- "to weep, lament," garzišn "complaint;" Mod.Pers. geristan, geryidan "to weep," gelé "gripe, complaint, lamentation;" Kurd (Kurm.) girižin/giriž- "to be grumpy, growl;" Av. gərəz- "to lament, weep;" cf. Skt. grah "to complain;" Proto-Ir. *garz- "to lament, weep."

An expression of discontent, regret, pain, censure, resentment, or grief; lament; faultfinding (Dictionary.com).

M.E. compleynte, from O.Fr. complainte "complaint, lament," noun from complaindre "to lament," → complain.

Verbal noun of garzidan, → complain.