WordNet
n. total cost for all units bought (or produced) divided by the number of units
Wikipedia
In economics, average cost and/or unit cost is equal to total cost divided by the number of goods produced (the output quantity, Q). It is also equal to the sum of average variable costs (total variable costs divided by Q) plus average fixed costs (total fixed costs divided by Q). Average costs may be dependent on the time period considered (increasing production may be expensive or impossible in the short term, for example). Average costs affect the supply curve and are a fundamental component of supply and demand.
$$AC=\frac{TC}{Q}$$
Usage examples of "average cost".
In just twenty-two months BTT had happily accepted 8,624 corpses for full-body suspension at an average cost of $9,700 each, pay.
At an average cost of $450,000 to train a case officer, rebuilding the Clandestine Service is a significant investment.
In 1967, the average cost of a hospital room in America increased 15 per cent.
Lets assume the average cost is twenty percent of that on Old Earth.
Last week we served a daily average of 42,392 lunches in Greater New York at an average cost to the consumer of twenty-three and seventeen-hundredths cents.
I know that the average duration from discovery of a potential drug to its FDA approval and marketing is about twelve years, and the average cost is somewhere around two hundred million dollars.
All these trial balloons make their way into the average cost of a book.
You take the population of vehicles in the field (A) and multiply it by the probable rate of failure (B), then multiply the result by the average cost of an out-of-court settlement (C).
At the same time the annual import of Oregrounds iron from Sweden amounted to about 20,000 tons, and of bars and slabs from Russia about 50,000 tons, at an average cost of 35L.
The long and tedious journey had killed half of them before they could be landed at Brindisium, and their average cost had been at least half as much again as that of the lions.