Q From Arthur Middleton: In the British TV series Are You Being Served a cat is often referred to as a moggy (I’m not sure of the spelling). Can you explain the derivation of this?
A Though I have to tell you that Are You Being Served has hardly been shown on British televisions for the better part of twenty years, that word is still common, often spelled moggie and sometimes shortened to mog. The latter often refers to a feline of undistinguished type and manners, the cat equivalent of a mongrel dog, but in general usage the former is just a pet name for any domesticated cat. It seems to be from Maggie, the affectionate short form of Margaret. In the eighteenth century, this was applied as a name for a cow or calf. In the nineteenth century it could refer to an untidily dressed woman or slattern. It was only in the twentieth century that it became a pet name for a cat. How or why the sense shifted in this way is not understood. Eric Partridge, in his Dictionary of Historical Slang implies that the cat sense may be Cockney rhyming slang, but I can find no evidence for that origin.