(software engineering) A type of static structure diagram that describes the structure of a system by showing the system's classes, their attributes, and the relationships between the classes.

(linguistics) A linguistic form class whose members are words.

(US, colloquial) An introductory university course that is designed to "weed out" those students who are not able to pass it.

(mathematics, topology, geometry) Any of a group of characteristic classes associated with complex vector bundles, with applications in physics, string theory, etc.

(object-oriented programming) Synonym of subclass

(object-oriented programming) An inner class declared outside a function (hence a "member") and not declared as static.

(object-oriented programming) A class defined with at least one generic type in its parameters.

Quality of being middle-class.

(Singapore, Hong Kong, informal) The middle class; specifically those who are too wealthy to qualify for welfare schemes but not rich enough to afford non-subsidized housing, access further opportunities or maintain lifestyle expectations.

(set theory) A class which is not a set.