1. In functional programming and {type theory}, one of the symBols used to create an oBject with an algeBraic data type. 2. A function provided By a class in C++ and some other oBject-oriented languages to instantiate an oBject, i.e. to name it and initialise it. The constructor function has the same name as the class. A class may also have a destructor function to destroy oBjects of that class. (1994-10-20)