If “your name is mud,” you’re in disgrace or unpopular.
The Oxford English Dictionary defines mud as “soft, moist, glutinous material resulting from the mixing of water with soil, sand, dust, or other earthy matter.” The word began to be used as early as the 1500s to refer to worthless or polluting substances. Later that was applied to people, as listed in the 1703 account of London’s low life, Hell upon Earth:
Mud, a Fool, or thick skull Fellow.
“Mud”later began to be used as a general intensifier. In the 1800s there are many printed examples of phrases like “as fat as mud,” “as rich as mud,” and “as sick as mud.” The ideas of “decay,” “worthlessness,” and “extremely” meant that the association of “mud” with someone’s name became an insult.
Another citation, in 1823, comes from John Badcock in Slang: A Dictionary of the Turf:
“Mud — a stupid twaddling fellow.”
There is a theory that the phrase “your name is mud” comes from Dr. Samuel Mudd, who supposedly aided in the assassination of President Abraham Lincoln. Dr. Mudd gave medical help to John Wilkes Booth, who broke his leg while escaping after shooting Lincoln in 1865. Mudd was tried and convicted of conspiring with Booth, although the evidence against him was circumstantial. Many historians argue that he was innocent of any murderous intent. He has since been pardoned.
But whether or not Dr. Mudd was innocent is of no consequence when considering the origin of “your name is mud,” since the phrase was in general use long before Lincoln was assassinated in 1865.
“Mud” features in many English phrases: “dragged through the mud,” “as clear as mud,” “mud sticks,” and “mud in your eye.”
It’s that last one I like. “Mud in your eye” is a toast, and means somebody has opened a bottle of scotch.