a floor. Rhyming slang, on the name of a legendary Irish rebel. The earliest of three uses for the rhyme; however, the second sense, 'a whore' is obsolete UK, 1857.

a door. Rhyming slang, on the name of a legendary Irish rebel. This is the only sense of the word also recorded in the US, where it is sometimes misspelt Rory O'Moore UK, 1892