Just to make it more confusing.

In the steel world, they divide steels (all of which are alloys) into three basic classes. Carbon, Alloy, and Stainless steels. In this context, the alloy steel category includes steels with various alloying elements, such as chrome, molybdenum (ie. CrMo), nickel, manganese, vanadium, etc. added in significant quantities to improve strength toughness or other desired properties.

These are usually used in combinations and the steel will be classed by the the elements mixed in highest quantities, such as Chromoly, nickel/chrome/moly, boron, manganese, or one that was popular for bikes a while back; nivachrome (nickel/vanadium/chrome).

BITD, the term alloy was popularized in the bicycle world as light alloy, meaning aluminum which is a relatively recent innovation (50s/60s) when it began to supplant steel in things like hubs, handlebars and cranks. Later, light alloy was shortened to alloy, and I still consider it shorthand for aluminum when used alone.

So alloy is another of those words with multiple meanings depending on the context.