To reduce in grade, rank, or status; demote. To lower in dignity; dishonor or disgrace: a scandal that degraded the participants. To lower in moral or intellectual character; debase. To reduce in worth or value: degrade a currency. To impair in physical structure or function. Geology To lower or wear by erosion or weathering. To cause (an organic compound) to undergo degradation. To fall below a normal state; deteriorate. To undergo degradation; decompose: a chemical that degrades rapidly.