Cockney slang hides its own rhyme by dropping the word that rhymes

In 19th-century East London, Cockney rhyming slang replaced everyday words with rhyming phrases - 'feet' became 'plates of meat', 'stairs' became 'apples and pears'. Once established, speakers habitually dropped the rhyming half, so 'plates of meat' shortens to just 'plates'. That truncation hides the rhyme that explains the phrase, turning the slang into an in-group code rather than obvious wordplay.

— Julian Franklyn, A Dictionary of Rhyming Slang — Routledge & Kegan Paul, 1960
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