lamentation (n.) Look up lamentation at
late 14c., from Old French lamentacion "lamentation, plaintive cry," and directly from Latin lamentationem (nominative lamentatio) "a wailing, moaning, a weeping," noun of action from past participle stem of lamentari "to wail, moan, weep," from lamentum "a wailing," from PIE root *la- "to shout, cry," which probably is imitative. Replaced Old English cwiþan.

The biblical book of Lamentations (late 14c.) is short for Lamentations of Jeremiah, from Latin Lamentationes (translating Greek Threnoi), from lamentatio "a wailing, moaning, weeping" (see lamentation).