Words that start with R

Rust is what happens to iron when there is moisture around. Things will rust faster if there is any salt in the water, which happens often near the sea or if salt has been used to de-ice roads or href="/s/sidewalk">sidewalk.
Rust is a distinctive reddish-brown. It is common to see old cars falling apart from rust.

A rut is a kind of hole in the ground, usually on a path or unsealed road, that has been made by the wheels of vehicles.
You might also talk about a rut as a stage of your life where you don't seem to be progressing, as in "I feel like I am stuck in a rut".

Rye is a cereal very closely related to wheat. It is grown mainly to make flour from to make into rye bread. It is also used as animal feed and to make some kinds of whiskey.