subs. (old).—1.  A key; specifically a master key. [From DUP or DUB, to open; to do up; see verb, sense.] For synonyms, see LOCKSMITH’S DAUGHTER.

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  1789.  G. PARKER, Life’s Painter, p. 153. A bunch of young DUBS by her side, which are a bunch of small keys.

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  1821.  D. HAGGART, Life, Glossary, p. 171. DUB, a key.

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  1839.  W. H. AINSWORTH, Jack Sheppard [1889], p. 39. That’s the kinchin as was to try the DUB for us, ain’t it? muttered Smith.

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  Verb (old).—To open, ‘DUB your mummer’ = Open your mouth. Cf., DUBBER; ‘DUB the jigger’ = open the door.—See quot., 1848. Also by confusion, to shut or fasten.

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  1567.  HARMAN, A Caveat or Warening for Common Cursetors [E.E.T.S., 1869], p. 85. DUP the gygger, and maund that is bene shyp.

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  1596.  SHAKESPEARE, Hamlet, iv. 5. Then up he rose and donned his clothes, and DUPPED the chamber door.

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  1848.  DUNCOMBE, Sinks of London Laid Open, p. 106. DUB the jigger, fasten the door.

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