subclass

2. In biology, a rank below class and above order in the classification of living things.

The subclass Mammalia includes all animals that feed their young with milk.

3. In computer programming, a class that inherits properties and methods from another class.

The programmer created a subclass to reuse code from the parent class.

4. A secondary or lesser class within a broader system or society.

The novel explores the lives of a social subclass often ignored by history.