What is the meaning of variance?

noun

• An event that departs from expectations.
  • synonyms: discrepancy, variant
• Discord that splits a group.
  • synonyms: division
• The second moment around the mean; the expected value of the square of the deviations of a random variable from its mean value.
• A difference between conflicting facts or claims or opinions.
  • usage: "a growing divergence of opinion"
  • synonyms: discrepancy, disagreement, divergence
• The quality of being subject to variation.
  • synonyms: variability, variableness
• An official dispensation to act contrary to a rule or regulation (typically a building regulation. )
  • usage: "a zoning variance"
• An activity that varies from a norm or standard.
  • usage: "any variation in his routine was immediately reported"
  • synonyms: variation