Personally, I define waste as follows:
Type A Waste is spending public money on completely unnecessary things. A $500,000 study of the sex life on the yellow-bellied red-crested snail darter is an example of this.
Type B Waste is spending public money on things that are arguably necessary, but spending excessively high amounts of money relative to the amount of goods/services purchased. For example, suppose the Navy needs 50,000 new computers to support its business processes. An impartial cost analysis determines that the required performance level and life-cycle supportability can be achieved at a cost of $2,000 per computer, or a total cost of $100,000,000.
However, because Senator Larson E. Pettifogger's biggest campaign contributor and drinking buddy, Joe Schlocker, owns a computer business, and because the Senator is an effective log-roller, the Navy is told to skew the cost analysis in favor of the Schlocker Enterprises computer at $5,000 apiece, or $250,000,000, on pain of getting long-lead items for their next aircraft carrier deleted in the next House-Senate budget reconciliation conference--an aircraft carrier that all parties, interested and disinterested alike, agree is necessary for the Navy to perform its mission in support of American foreign policy and national strategy, and that delay in procuring that aircraft carrier is going to degrade the Navy's ability to perform its mission during the period it otherwise would be available.
This means, first, that the nation has paid $150,000,000 more than needed for a specific good.
Second, if the Navy resists this pressure, the Navy will pay a price--in being good stewards of the public's money, they will be less capable of performing their mission. However, Senator Pettifogger isn't the only Senator playing this game. If this happens often enough and long enough, the Navy will be virtuous in managing the public's money--and unable to perform its mission.