1. A change in something that makes it better, more accurate, or more effective.
2. A change which someone makes in his or her behavior or attitude by making or becoming suitable or adjusting to circumstances.
3. In sociology, a process of modifying, adapting, or altering individual or collective patterns of behavior is order to bring them into conformity with other such patterns; for example, as with those provided by a cultural environment.
4. Regarding insurance, the act of determining the amount of indemnity that the party insured is entitled to receive under the policy and of settling a claim.
5. A means of modifying something; especially, a physical mechanism that requires regulating or correcting.

A reduction in a government budget deficit, which can result from a reduction in government expenditures, an increase in tax revenues, or both at the same time.

The alteration of the engine idle speed of a vehicle or other motor-driven machine.