Real Dictionary

overhead
You use overhead to indicate that something is above you or above the place that you are talking about.

overhead in Accounting
Overheads are the regular and essential expenses of running a business, such as salaries, rent, and bills.

overhead in American English
located or operating above the level of the head
adjective: situated, operating, or passing above, aloft, or over the head
adverb: over one's head; aloft; up in the air or sky, esp. near the zenith
noun: the general, fixed cost of running a business, as rent, lighting, and heating expenses, which cannot be charged or attributed to a specific product or part of the work operation

overhead in British English
adjective: situated or operating above head height or some other reference level
adverb: over or above head height, esp in the sky
noun: a stroke in racket games played from above head height