'Subclass' definitions:

Definition of 'subclass'

(from WordNet)
noun
(biology) a taxonomic category below a class and above an order

Definition of 'Subclass'

From: GCIDE
  • Subclass \Sub"class`\, n. One of the natural groups, more important than an order, into which some classes are divided; as, the angiospermous subclass of exogens. [1913 Webster]