'pedagogue' comes into English via Middle English and Old French from Latin 'pedagogus', ultimately from Greek 'paidagōgos', where 'paidos/paid-' meant 'child' and 'agogos' meant 'leader' or 'guide'.

'pedagogue' passed from Greek 'paidagōgos' into Latin as 'pedagogus', then into Old French and Middle English, eventually becoming the modern English 'pedagogue'.

Originally it referred to a slave or attendant who led children to school ('leader of children'); over time it came to mean 'teacher' and in later use often acquired the additional sense of a 'pedantic' or overly formal instructor.