Spot the Frippet: rust.

 A rustbucket used to mean a very old car:

photo by Tyson Hepburn

 but cars don't rust much any more. There's still plenty of rust about, though. It's a mixture of iron and oxygen and it can be very beautiful:

photo by Laitr Keiows

Iron and steel go rusty if they get damp (unless it's stainless steel) and so you probably aren't far from a bit of rusty metal - an old steel can, perhaps, or a radiator that's leaked a little, or an old road sign, or a screw:

photo by User:Paulnasca

And then there's the kind of rust that infects plants, which is a fungus. It makes parts of the plant go rust-brown:

coffee leaf. Photo by Smartse

In fact the word rust can be used of anything the colour of rust, whether it's a carpet or a dog:

photo by tomcue2

Talents and knowledge rust, too. How good is the foreign language you haven't spoken since school? Or your current knowledge of your sacred book? Or your ability to play chess?

Never hard to spot rust, is it.

Spot the Frippet: rust. The word was rūst in Old English.