any compound of oxygen with another element or a radical
"The rust that formed on the iron gate was primarily an oxide of iron."
A binary chemical compound of oxygen with another chemical element.
"Rust is a common oxide formed when iron reacts with oxygen in the presence of moisture."
In plain English: An oxide is any substance made by combining oxygen with another element.
"Rust is an oxide that forms when iron comes into contact with oxygen and moisture."
Usage: Use this term to describe any substance formed when oxygen chemically bonds with one other specific element, such as rust being iron oxide or silica in sand. Avoid using it for mixtures containing multiple elements besides the primary metal and oxygen unless they form a distinct compound structure.
The word "oxide" was coined in the 18th century as an archaic French blend of oxygène (oxygen) and -acide. It entered English to describe compounds containing oxygen, combining these two scientific concepts into a single term.