Cruelty is a related term of barbarity.

In uncountable|lang=en terms the difference between cruelty and barbarity

is that cruelty is (uncountable) an indifference to suffering or positive pleasure in inflicting suffering while barbarity is (uncountable) crudity.

In countable|lang=en terms the difference between cruelty and barbarity

is that cruelty is (countable) a cruel act while barbarity is (countable) a crude act.

As nouns the difference between cruelty and barbarity

is that cruelty is (uncountable) an indifference to suffering or positive pleasure in inflicting suffering while barbarity is (uncountable) the state of being barbarous; brutality.