pedagogue

Short definition from Wiktionary

Noun

1. 1
   A teacher or instructor of children; one whose occupation is to teach the young.
2. 2
   A pedant; one who by teaching has become overly formal or pedantic in his or her ways; one who has the manner of a teacher.
3. 3
   A slave who led the master's children to school, and had the charge of them generally.

Verb

1. 1
   To teach.