The English language word "pedant" comes from the Frenchpédant (used in 1566 in Darme & Hatzfeldster's Dictionnaire général de la langue française) or its older mid-15th century Italian source pedante, "teacher, schoolmaster". (Compare the Spanish pedante.) The origin of the Italian pedante is uncertain, but several dictionaries suggest that it was contracted from the medieval Latinpædagogans, present participle of pædagogare, "to act as pedagogue, to teach" (Du Cange). The Latin word is derived from Greek παιδαγωγός, paidagōgós, παιδ- "child" + ἀγειν "to lead", which originally referred to a slave who escorted children to and from school but later meant "a source of instruction or guidance".
Obsessive-compulsive personality disorder is also in part characterized by a form of pedantry that is overly concerned with the correct following of rules, procedures and practices. Sometimes the rules that OCPD sufferers obsessively follow are of their own devising, or are corruptions or re-interpretations of the letter of actual rules.
"A Man who has been brought up among Books, and is able to talk of nothing else, is what we call a Pedant. But, methinks, we should enlarge the Title, and give it to every one that does not know how to think out of his Profession and particular way of Life."—Joseph Addison, Spectator 1711.
"The pedant is he who finds it impossible to read criticism of himself without immediately reaching for his pen and replying to the effect that the accusation is a gross insult to his person. He is, in effect, a man unable to laugh at himself."—Sigmund Freud, The Ego and the Id.
"The term, then, is obviously a relative one: my pedantry is your scholarship, his reasonable accuracy, her irreducible minimum of education and someone else’s ignorance."—H. W. Fowler, Modern English Usage
"If you're the kind of person who insists on this or that 'correct' use... abandon your pedantry as I did mine. Dive into the open flowing waters and leave the stagnant canals be... Above all, let there be pleasure!"—Stephen Fry
"Ben is a crossword-doer, a dictionary-lover, a pedant."-Julian Barnes