oncost

from The Century Dictionary.

• noun Additional costs; extra expenses.
• noun In coal-mining, the cost of upkeep, making and maintaining shafts and roads, pumping, etc. The engineers and others employed on this work are paid by time.
• noun The indirect expenditure incurred for the purpose of increasing the productive power of organized labor.
• Noting work done on time wages; also, noting men who work on such terms: as, oncost-men.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Accounting), Brit. In cost accounting, expenditure which is involved in the process of manufacture or the performance of work and which cannot be charged directly to any particular article manufactured or work done (as where different kinds of goods are produced), but must be allocated so that each kind of goods or work shall bear its proper share.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Additional costs; extra expenses.
• noun finance Overhead (expense)
• noun The cost of upkeep, making and maintaining shafts, roads, pumping, etc.
• noun Scotland The indirect expenditure incurred for the purpose of increasing the productive power of organised labour.