Definition of "rust" []

• Any of various powdery or scaly reddish-brown or reddish-yellow hydrated ferric oxides formed on iron and iron-containing materials by low-temperature oxidation in the presence of water. (noun)
• Any of various metallic coatings, especially oxides, formed by corrosion. (noun)
• A stain or coating resembling iron rust. (noun)
• Deterioration, as of ability, resulting from inactivity or neglect. (noun)
• Botany Rust fungus. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "If GM / Chrysler go, I guarantee you that the term rust belt will take on a whole new meaning, and dimension."
• "Oxidation can even cause the breakdown of hard metals, which we call rust."
• "There they were, run off their legs, and no maintenance, and then after the war, it fell apart under us, we had what we called rust bucket campaigns, we had a situation for a long time where these carriages, and you know they carry nearly, well not nearly all, but a big proportion of Sydney to work."