Know your arse from your elbow

Posted by Smokey Stover May 01, 2009 at 16:08In reply to Know your arse from your elbow posted by Steve Buckley on April 22, 2009 at 08:59:

I would like to know the origin of 'your arse from your elbow'. I live in Spain and the other day I noticed that the word arse is CULO and elbow is CODO.

Personally, I think the similarity of the words in Spanish is just a coincidence.

The expression in English is fairly recent. The Oxford English Dictionary quotes this from 1930: "R. BLAKER Medal without Bar xiii. 69 'But nor 'an 'un' (this phrase was his masterpiece of thoughtful emphasis), 'nor 'an 'un of us knows 'is ears from 'is elbow when it comes to learning--learning like you orficers have got up your sleeves.'

Was Blaker using a euphemism for the real thing? The OED's first citation of "arse from elbow" is from 1944. I would not be surprised to learn that the English-speaking combatants in World War II made the phrase popular, or perhaps more popular, although I don't know this for a fact.
SS