I read on wikipedia (no source) that Malevich called Rudchenko "a mere constructivist" in 1917 after seeing his latest works in an exhibition. After some hours of research online as well as in Farthing's "Kunstgeschichte" and Thames&Hudson "Art since 1900" it seems that this may be the earliest use of the term if it's true, but still no historical uses in these books explain the etymology. Now supposedly the Realist Manifesto (Naum Gabo, 1920) not only has laid foundations of constructivists' creating in the following years, but has also used the term "Constructivism", but I have failed to find that term, although I also failed to find an authentic text in English online.

In summation, I am unfamiliar with the historical stem of the term constructivism. Also since Deconstructivism (in both Derrida's writings as well as in the architecture movement) seems unassociated with the Russian Constructivism, then likewise: does it itself strongly rely on any historical term, or is it merely concerned with deconstructing the timeless architectural functionalities superposing them to the architectural tendencies contemporary to Deconstructivism (modernism and post-modernism), or respectively in the case of Derrida, solely concerned with disassembling the supposedly existing relationship between text and meaning, rather than referring to any historical constructivism?