A group of swans.
Specifically, mourning.
The act of lamenting.
A sorrowful cry; a lament.
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 mallards (ducks).
The act of lining a canal with puddle to make it watertight.
The action of forming a puddle.
The first true industrial process to produce steel from pig iron.
A behaviour in which animals like butterflies seek out moist substances to obtain nutrients.
The process of working clay, loam, pulverized ore, etc., with water, to render it compact, or impervious to liquids.