1560s, from M.Fr. aristocracie (Mod.Fr. aristocratie), from L.L. aristocratia, from Gk. aristokratia "government, rule of the best," from aristos "best" (originally "most fitting," from PIE *ar-isto-, superlative form of *ar- "to fit together") + kratos "rule, power" (see -cracy). At first in a literal sense; meaning "rule by a privileged class" (best-born or best-favored by fortune) is from 1570s and became paramount 17c. Hence, the meaning "patrician order" (1650s). In early use contrasted with monarchy; after French and American revolutions, with democracy.