What is the meaning of Overage?

Having an age that is greater than a stipulated minimum.

Too old to be of use in a particular situation.

To have too long an aging process.

A surplus of inventory or capacity or of cash that is greater than the amount in the record of an account.

Excess; a state of being more than it ought to be.

Any additional sums payable following the purchase of land, calculated on a prearranged basis, on the occurrence of certain specified events that are deemed to increase the value of that land; usually in the context of the development and further sale of that land.

Source: wiktionary.org