A more thorough explanation:

Definition: Rent equal to or nearly equal to the full annual value of the property; excessively or unreasonably high rent.

Example: If a small apartment is worth $1,000 per month, but the landlord charges $1,500 per month, that would be considered rack rent.

Explanation: Rack rent is when a landlord charges an unreasonable amount of rent for a property. In the example given, the landlord is charging $500 more than the property is worth, which is an example of rack rent.