In African-American slang, a ''Murphy'' is a type of scam in which the victim pays for something in advance, usually a prostitute, but the 'goods' are never delivered.
In British slang, a ''Murphy'' is a potato.
''The Murphy'' is a slang term for replacing stolen goods with worthless, inferior products.
Meaning:
Its source is Murchad, an Irish Gaelic name meaning "Sea warrior."