The Collaborative International Dictionary of English v.0.48:
Overhead charges \O`ver*head" char"ges\, Overhead expenses
\O`ver*head" expenses\, etc. (Accounting)
Those general charges or expenses in any business which
cannot be charged up as belonging exclusively to any
particular part of the work or product, as where different
kinds of goods are made, or where there are different
departments in a business; -- called also fixed charges,
establishment charges, or (in a manufacturing business)
administration charges, selling charges, and
distribution charges, etc.
[Webster 1913 Suppl.]