#necessity  the condition of being essential or indispensable
  supertype:  need__demand  a condition requiring relief; "she satisfied his need for affection"; "God has no need of men to accomplish His work"; "there is a demand for jobs"
  subtype:  requisiteness__requisitenes  the state of being absolutely required
  subtype:  urgency  the state of being urgent; an earnest and insistent necessity
     subtype:  hurry__haste  a condition of urgency making it necessary to hurry; "in a hurry to lock the door"
     subtype:  imperativeness__insistence__insistency__press__pres  the state of urgently demanding notice or attention; "the press of business matters"
     subtype:  criticalness__criticality__cruciality  a state of critical urgency

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