subclass

n. secondary class; subdivision of a class; category of related organisms within a class (Biology)

Subclass may refer to:Subclass (biology), a taxonomic rank intermediate between class and superorderSubclass (computer science), a class that is derived from another class or classesSubclass (database theory), a class which inherits its data members and methods of their superclassesSubclass (set theory), a class contained in some other class in the same way that a subset is a set contained in some other set.
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Noun
1. (biology) a taxonomic category below a class and above an order
(hypernym) taxonomic group, taxonomic category, taxon
(classification) biology, biological science

(n.)
One of the natural groups, more important than an order, into which some classes are divided; as, the angiospermous subclass of exogens.
  

derived class