dickory dock, n. — Green’s Dictionary of Slang

dickory dock n.

[rhy. sl. The nursery rhyme from which this comes is itself a Romany creation. According to Gerald Denley: ‘Hickory is derived from the Romany “Ek Ore” meaning one o’clock. The word for one in Romany varies according to the tribe, so it is either “ek”, “yek” or “ik”. The stress is on the first vowel, so that “ek ore” is pronounced as one word. Dickory Dock is often described as London rhyming slang. But it could mean the dock where the dick puts you when you are caught choring or stealing.’]

1. (also dickery (dock), dicky) a clock (cf. hickory-dock n.).

1921		Western Gaz. 25 Mar. 10/5: [advert] Dickory Dock — 7 o’clock the bains trip up to bed.
a.1945		L. Payne private coll. n.p.: Clock Dickery Dock.
1946		St. Vincent Troubridge ‘Some Notes on Rhyming Argot’ in AS XXI:1 Feb. 46: hickory dock. A clock. (Origin uncertain, American or English.) Probably American in this form. The English is Dickory Dock, from the old English nursery rhyme. Another example of word corruption.
1960		J. Franklyn Dict. of Rhy. Sl.
1971		J. Jones Rhy. Cockney Sl.
1976		(ref. to 1930s–70s) R. Barnes Coronation Cups and Jam Jars 206: Dicky – Clock.

2. the penis [cock n.³ (1)].

1972		Dodson & Saczek Dict. of Cockney Rhy. Sl.
1980		Maledicta IV:2 (Winter) 189: Dick or dickie [...] is also short for dickory-dock (rhyming slang on cock).

3. a sock.

1960, 1975

Wentworth & Flexner DAS.