Definition of "dup"

dup

/dʌp/

verb
third-person singular simple present dups, present participle dupping, simple past and past participle dupped
1. to open (a door, gate etc.)
  Quotations
  Then up he rose and donned his clothes, / And dupped the chamber door;
  c. 1599–1602 (date written), William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act IV, scene v]
  He had seen, that Maundy Thursday afternoon, dupping their chamber door in all maaaaaaa innocence.
  1964, Anthony Burgess, Nothing Like the Sun