Meaning

noun an artistic movement in France beginning in 1907 that featured surfaces of geometrical planes

originFrom French cubisme. One story is that, in 1908, as a new canvas by Braque was being carried past, someone said, “Encore des cubes! assez de cubisme!”. The quotations below ascribe the coinage to Matisse. Sometimes attributed to French art critic Louis Vauxcelles who popularized the term. See also the word cube (from Latin cubus, from Ancient Greek κύβος (kúbos)).

Etymology from Wiktionary, CC BY-SA 3.0