lament (n.)
1590s, "expression of sorrow or grief," from Middle French lament and directly from Latin lamentum "a wailing, moaning, weeping" (see lamentation). From 1690s as "a mourning song."
lament (v.)
mid-15c., back-formation from lamentation or else from Old French lamenter "to moan, bewail" (14c.) and directly from Latin lamentari "to wail, moan, weep, lament," from lamentum "a wailing, moaning, weeping." Related: Lamented; lamenting.