What is the meaning of Lamentation?

The act of lamenting.

A sorrowful cry; a lament.

Specifically, mourning.

lamentatio, (part of) a liturgical Bible text (from the book of Job) and its musical settings, usually in the plural; hence, any dirge

A group of swans.

lamentation, loud/ostentatious plaint

lamentation, loud/ostentatious plaint

Source: wiktionary.org