Words: pedant, n.

COMBINING A suggestion of both pedagogue and pedestrian, pedant has become the word we apply to anyone showing a ponderous attention to academic detail. Shakespeare and Ben Jonson used the word with no derogatory intent as a synonym for teacher, which would seem to confirm the OED's claim that the word stems from the Italian pedante, a schoolmaster. Yet if the original meaning was much the same as pedagogue, one might expect at least some classically educated Englishmen to have adopted the spelling paedant, but there is no evidence of that ever having happened.

The same Italian word, pedante, however, also meant "travelling on foot", so perhaps the picture of a pedestrian pedagogue is not so far from the mark.