corrosion
n. uncountablen. the slow damage or destruction of a metal surface by water, air, or chemicals. You see this most often as rust on old cars or pipes.
n. the gradual destruction of materials, usually metals, by chemical or electrochemical reaction with their environment. Often used metaphorically to describe the slow decay of abstract concepts like trust or power.
The salt in the air caused heavy corrosion on the bridge.
Engineers must inspect the underwater supports regularly to check for signs of corrosion caused by the saltwater.
While the physical corrosion of the hull was manageable, the systemic corrosion of the crew's morale proved to be the more significant threat to the mission's success.
From Middle English corrosioun, from Old French corrosion, or its source, Late Latin corrōsiōnem, accusative singular of corrōsiō (“gnawing away, corroding”), from Latin corrōdō (“gnaw away, corrode”).
Uncountable in its general sense; can be countable when referring to specific chemical types or instances of the process.