noun

• (art) A Russian movement in modern art characterized by the creation of nonrepresentational geometric objects using industrial materials.
• (mathematics) A philosophy that asserts the need to construct a mathematical object to prove it exists.
• (philosophy, psychology) A psychological epistemology which argues that humans generate knowledge and meaning from their experiences.
  "There is no single theory of constructivism. In fact, there are many shades and varieties of constructivism spanning a range of perspectives. There is also no single individual who can be identified as the founder of constructivism. In fact, rather than tracing a linear development along one line of philosophical thought, constructivism seems to circumscribe a set of thinkers, theories and approaches that spring from a plethora of historical and cultural origins."