noun

• (figurative) A feeling of completeness; the experience of an emotional conclusion, usually to a difficult period.
  "to find emotional closure"
• (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.
  "Instead, make f and g input arguments, and use the closure around the inner function so that this code works with any two functions that you provide. Closures are important features that work amazingly well with higher-order functions; I’ll review them in section 4.4."
• (mathematics) The smallest set that both includes a given subset and possesses some given property.
• (topology, of a set) The smallest closed set which contains the given set.
  "7 THEOREM The closure of any set is the union of the set and the set of its accumulation points."

verb

• (transitive, politics) To end the parliamentary debate on (an issue) by closure.
  "At any time they could have stopped discussion by closuring amendments and by closuring the clause under discussion."