Device invented by 'Cockney geezers' to conceal the subject of conversations from eavesdroppers and/or the police. Examples include: apples and pears (stairs), Barnet Fair (hair), butchers' hook (look) and Chalfont St. Giles (piles). Not to be confused with Cockney Poetry.
[n] slang that replaces words with rhyming words or expressions and then typically omits the rhyming component; "Cockney rhyming slang"