1. To decrease something to some level: The drought reduced the stream to a trickle.

2. To bring someone to some humbler, weaker, difficult, or forced state or condition: The illness had reduced them almost to emaciation. The sight of her mother reduced her to tears. The army reduced him from a command post to a desk job.

3. To bring someone to such a humble, weak, or desperate state or condition that he or she does something drastic: The Depression reduced many to begging on the street.

4. To damage or destroy something, leaving it in some lesser state: The blaze reduced the warehouse to ashes.

5. To make something shorter and simpler; summarize something: Their entire business philosophy can be reduced to "The customer is always right."