the world > physical sensation > cleanness and dirtiness > dirtiness > pollution or defilement > [noun] > specific impurities > incrustation > on metal > rust (4)
rusteOE
A red, orange, or yellowish-brown substance which forms progressively as a flaking, permeable coating on the surface of iron and its alloys as a…
ewre1597
? Rust, oxide.
Subcategories:
— rusting (1)
— which weeps through scale adherent to boilers (1)