porridge [M16th] At first porridge was a soup thickened with barley. The word is a 16th-century alteration of pottage [ME], which in turn comes from Old French potage ‘something put in a pot’. The porridge we are familiar with, consisting of oatmeal boiled in water or milk, is mentioned in the 1640s. The informal use of porridge to mean ‘prison’ dates from the 1950s. It probably derives from porridge as a typical prison food, though it might be based on a pun involving two meanings of stir, one as in ‘stir the porridge’ and the other a slang term for ‘prison’, which is perhaps from Romany sturbin ‘jail’ (see romani words).