Collateral adjective
A collateral adjective is an adjective whose word origin is different from the noun it represents. English has many collateral adjectives from French, Latin, and Greek because many English words come from those languages. For example, the adjectives for the native English words "horse" and "moon" are "equine" and "lunar". "Equine" comes from the Latin "equus", and "lunar" comes from the Latin "luna" and so  the study of horses is called "equine science", and the calendar for the moon is called the "lunar calendar".