Definition of "closure"

closure

/ˈkləʊ.ʒə(ɹ)/

noun
countable and uncountable, plural closures
1. An event or occurrence that signifies an ending.
2. A feeling of completeness; the experience of an emotional conclusion, usually to a difficult period.
3. A device to facilitate temporary and repeatable opening and closing.
4. (programming) An abstraction that represents a function within an environment, a context consisting of the variables that are both bound at a particular time during the execution of the program and that are within the function's scope.
5. (mathematics) The smallest set that both includes a given subset and possesses some given property.
6. (topology, of a set) The smallest closed set which contains the given set.
  Quotations
  The closure ( T {\displaystyle {\mathfrak {T}}} -closure) of a subset A of a topological space ( X , T ) {\displaystyle (X,{\mathfrak {T}})} is the intersection of the members of the family of all closed sets containing A. […] / 7 THEOREM The closure of any set is the union of the set and the set of its accumulation points.
  1955 [Van Nostrand Reinhold], John L. Kelley, General Topology, 2017, Dover, page 42
7. The act of shutting; a closing.
8. The act of shutting or closing something permanently or temporarily.
  Quotations
  Those who have advocated the closure of the G.C. have so far failed to say by which alternative route this North-to-West traffic could be carried.
  1960 December, B. Perren, “The role of the Great Central—present and future”, in Trains Illustrated, page 765
  Despite the line proving to be a useful strategic route for men and supplies to the British naval fleets stationed at Scapa Flow in both world wars, the Duke's legacy looked to have passed into history when it was listed for closure in the infamous Beeching report.
  2021 October 20, Paul Stephen, “Leisure and pleasure on the Far North Line”, in RAIL, number 942, page 48
9. That which closes or shuts; that by which separate parts are fastened or closed.
  Quotations
  I admire on this consideration your sending your last to me quite open, without a seal, wafer, or any closure whatever, manifesting the utter openness of the writer.
  1729 November 28, Alexander Pope, Letter to Jonathan Swift, 1824, The Works of Jonathan Swift: Containing Additional Letters, Volume 17, 2nd Edition, page 284
10. (obsolete) That which encloses or confines; an enclosure.
  Quotations
  O thou bloody prison […] / Within the guilty closure of thy walls / Richard the Second here was hacked to death.
  c. 1593 (date written), William Shakespeare, “The Tragedy of Richard the Third: […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene iii]
11. (politics) A method of ending a parliamentary debate and securing an immediate vote upon a measure before a legislative body.
12. (sociology) The phenomenon by which a group maintains its resources by the exclusion of others from their group based on varied criteria.
13. The process whereby the reader of a comic book infers the sequence of events by looking at the picture panels.
  Quotations
  The comic book reader performs closure within each panel, between panels, and among panels.
  2009, Randy Duncan, Matthew J. Smith, The Power of Comics: History, Form and Culture, page 166