Overhead is defined as something coming from above or the operating costs of a business.(noun)
The definition of overhead is relating to the operating costs of a business.(adjective)
An example of overhead used as an adjective is the phrase "overhead projections," which means how much money a company thinks it will use in an upcoming month, term or year.
See overhead in Webster's New World College Dictionary
See overhead in American Heritage Dictionary 4
Learn more about overhead