Residue

Remaining trace or quantity of something.

Residue is a remaining trace or quantity of something, often unwanted.

/ˈrezɪdjuu/

From Old French residu, from Latin residuum ‘that which remains’.

Residue is what's left behind after something has been used or removed, like the leftover food on a plate or tiny amounts of chemicals in water.

Residue is a common term in chemistry, referring to any substance left over after a chemical reaction
In winemaking, 'lees' is the sediment of dead yeast and other particles that settle at the bottom of a fermentation tank
The term 'residue' is used in archaeology to describe traces of past human activity

What is residue? It's a remaining trace or quantity of something
What causes residue? It can be caused by evaporation, chemical reactions, or simply being left behind
Can residue be harmful? It depends on the substance
some residues are harmless, while others can be toxic

remnant trace leftover

waste remnant

ash sediment deposit

sample material

chemical geological formation