socks, old

   One middle-class young man addresses another by this term in Martin Arrowsmith, by Sinclair Lewis. The Oxford English Dictionary mentions that Latin socius has occasionally been used by educated speakers to refer to an ally or colleague.

   Eric Partridge also gives the word as public school slang for a chum. It is tempting to make the link, though most students of Latin would presumably pronounce the ‘c’ in socius as in the word ‘social’, which derives from it, rather than as the ‘ck’ in ‘sock’.

   As it happens a special meaning of ‘sock’ developed in the nineteenth century. making it possible to refer to a favourite child by that term. This probably came about because of the expression ‘socklamb’, referring to a lamb raised by hand and kept as a pet. It seems most unlikely that this would have led to ‘old socks’ as a term of address, one which has wider currency than the single literary example given above would suggest. Schoolboy wit may well have made the connection between socius and ‘sock’.