demagogue: [17] A demagogue is literally a ‘leader of the people’. The word represents Greek demagōgós, a compound formed from demos ‘common people’ and agōgós ‘leader’. (This was derived from ágein ‘drive, lead’, a verb related to Latin agere ‘do’, and hence to its host of English descendants, from act to prodigal.) In ancient Greece the term was applied particularly to a set of unofficial leaders drawn from the common people who controlled the government of Athens in the 4th century BC, and whose irresponsible rule (as their critics saw it) has given demagogue a bad name ever since. => act, agent
demagogue (n.)
1640s, from Greek demagogos "popular leader," also "leader of the mob," from demos "people" (see demotic) + agogos "leader," from agein "to lead" (see act (n.)). Often a term of disparagement since the time of its first use, in Athens, 5c. B.C.E. Form perhaps influenced by French demagogue (mid-14c.).
demagogue (v.)
by 1964, American English, from demagogue (n.). Related: Demagogued; demagoguing.