noun

• (uncountable) An indifference to suffering or pleasure in inflicting suffering.
  "Fear of their cargo bred a savage cruelty into the crew. One captain, to strike terror into the rest, killed a slave and dividing heart, liver and entrails into 300 pieces made each of the slaves eat one, threatening those who refused with the same torture. Such incidents were not rare."
• (countable) A cruel act.
  "The Begums' ministers, on the contrary, to extort from them the disclosure of the place which concealed the treasures, were, […] after being fettered and imprisoned, led out on to a scaffold, and this array of terrours proving unavailing, the meek tempered Middleton, as a dernier resort, menaced them with a confinement in the fortress of Chunargar. Thus, my lords, was a British garrison made the climax of cruelties!"