A more thorough explanation:

Definition: Absorption is the process of including or incorporating something into something else. It can also refer to the application of rights guaranteed by the U.S. Constitution to actions by the states, the merger of one nation into another, a provision allowing seniority for union members in a postmerger collective-bargaining agreement, the rate at which property will be leased or sold on the market at a given time, or a sales method by which a manufacturer pays the reseller's freight costs.

• When a sponge soaks up water, it is an example of absorption.
• After the Civil War, the U.S. Constitution's rights were absorbed by the states.
• When one country is taken over by another, it is called absorption.
• In a postmerger collective-bargaining agreement, a provision allowing seniority for union members in the resulting entity is called absorption.
• The absorption rate of a property is the rate at which it will be leased or sold on the market at a given time.
• When a manufacturer pays the reseller's freight costs, it is called absorption or freight absorption.

These examples illustrate the different meanings of absorption. The first example shows absorption as a physical process, while the other examples show absorption as a legal or commercial process. In each case, something is being incorporated into something else.