From sub- + class.

• IPA: /ˈsʌbklæs/, /ˈsʌbklɑːs/

subclass (plural subclasses)

1. A secondary class within a main class.
   • 1959, "Steam's Finest Hour" edited by David P. Morgan, Kalmbach Publishing Co., referring to the R-1 Mountain class loco.

     These 4-8-2's, of which B&M eventually purchased 18 in various subclasses, could almost haul the tonnage of a T and more than made up for the slight deficiency by raising the maximum speed limit from 45 to 70 miles per hour, thanks to 73-inch drivers.

2. (taxonomy) A rank directly below class.
3. (object-oriented programming) An object class derived from another class (its superclass) from which it inherits a base set of properties and methods.

• subset
• child class, derived class, heir class

• superclass
• superset

• French: sous-classe

• French: sous-classe
• German: Unterklasse, Subklasse
• Portuguese: subclasse
• Russian: подкла́сс

• French: classe fille
• German: Kindklasse, Subklasse, Unterklasse
• Portuguese: subclasse
• Russian: подкла́сс

subclass (subclasses, present participle subclassing; simple past and past participle subclassed)

1. (transitive, computing) (in object-oriented programming) To create a subclass of (some class).

   I subclassed the Button class to create a more specialised FancyButton class for my user interface.

2. (transitive, computing) To cause (an object) to act as an instance of a subclass (by creating the desired subclass and instantiating an object of this subclass).
   • 2000, James D. Foxall, MCSD in a Nutshell: The Visual Basic Exams, page 93:

     Since Windows knows about these events, your application should be able to know about them as well. In order to accomplish this, subclass the window of a form or control, intercepting all of its events.

• (antonym(s) of “cause to act as a member of a subclass”): unsubclass