Muggles' Guide to Harry Potter/Magic/Mudblood

Overview
An offensive and insulting term for Muggle-born witches or wizards.

Extended Description
This term, which is bad enough that it rather shocks Hagrid when he first hears that it has been used, is a dreadful insult. Wizards who pride themselves on being "pure-blooded" use the term to suggest that Muggle parents or grandparents somehow pollute the person's blood.

Analysis
While the term is first used by Draco Malfoy in Harry Potter and the Chamber of Secrets, and is there seen as being a horrible insult, it is instructive to note that as the series continues, it is used more frequently; and with the increase in usage it loses its power.

Draco Malfoy uses "mudblood" to describe Hermione Granger, who is born of Muggle parents. Ron Weasley and Harry Potter see this as clear evidence that Draco is ruled by prejudice, and believe that this makes him likely to join Voldemort's organization. The reader perforce accepts Harry's point of view in this.

Ron tells Hermione that the term is used to refer to one with "dirty blood, common blood." While the term is not used in the book to refer to wizards with one Muggle parent, it seems that a wizard obsessed with "Blood purity" could consider such a person to have "polluted their blood", and so could use this term against Half-blood witches and wizards as well. It is interesting to look at the roster of characters in the series and see who could be equally tarred by this epithet. Of course, Harry's mother springs from Muggle roots, but interestingly Severus Snape had a Muggle father, and for that matter so did Voldemort himself.