Definitions:

1. An indifference to pleasure or pain. NOUN
   • The stolidness of the audience during the performance was a testament to the actor's lackluster execution.
2. Describes a demeanor or behavior characterized by a lack of responsiveness or outward emotional display. NOUN
   • Despite the tragic news, he face it with stolidness, showing no outward signs of grief or distress.
3. Refers to the quality or state of being stolid. NOUN
   • The stolidness of the old oak tree hinted at its centuries of weathering countless storms.

Synonyms:

• aloofness
• coldness
• detachment
• disinterest
• dispassion
• dullness
• emotionlessness
• stoicism