playfulness

As a noun playfulness

is the quality of being playful.

As an adjective serious is

without humor or expression of happiness; grave in manner or disposition; earnest; thoughtful; solemn.

As nouns the difference between playfulness and enjoyment

is that playfulness is the quality of being playful while enjoyment is (uncountable) the condition of enjoying anything.

As a noun playfulness

is the quality of being playful.

As an adjective undefined is

lacking a definition or value.

As nouns the difference between disobedience and playfulness

is that disobedience is refusal to obey while playfulness is the quality of being playful.

Glee is a synonym of playfulness.

As nouns the difference between glee and playfulness

is that glee is (uncountable) joy; merriment; mirth; gaiety; particularly, the mirth enjoyed at a feast while playfulness is the quality of being playful.

As nouns the difference between balance and playfulness

is that balance is a state in which opposing forces harmonise; equilibrium while playfulness is the quality of being playful.

As a verb balance

is to bring to an equipoise, as the scales of a balance by adjusting the weights.

As nouns the difference between gladness and playfulness

is that gladness is the state of being glad; joy while playfulness is the quality of being playful.

Cheerfulness is a related term of playfulness.

As nouns the difference between cheerfulness and playfulness

is that cheerfulness is the state of being cheerful; joy while playfulness is the quality of being playful.

Playfulness is a related term of sprightliness.

As nouns the difference between playfulness and sprightliness

is that playfulness is the quality of being playful while sprightliness is the property of being sprightly.