a combining form occurring in loanwords from Greek (aristocracy; democracy ); on this model used, with the meaning “rule,” “government,” “governing body,” to form abstract nouns from stems of other origin: mobocracy; bureaucracy.
comb. element forming nouns meaning "rule or government by," from Fr. -cratie or M.L. -cratia, from Gk. -kratia "power, might; rule, sway; power over; a power, authority," from kratos "strength," from PIE *kratus "power, strength" (see hard). The connective -o- has come to
be viewed as part of it. Productive in English from c.1800.