What does "pensiveness" mean?

A thoughtful or reflective state, especially if sad or melancholic.

Pensiveness

Common synonyms include: absorption, abstraction, brooding, brown study, castle building, castle-building.

noun

noun ·Rare ·Advanced level

Noun

1
A thoughtful or reflective state, especially if sad or melancholic. uncountable
"We left quietly so as not to disturb the widow's pensiveness."
2
deep serious thoughtfulness wordnet
3
persistent morbid meditation on a problem wordnet

"We left quietly so as not to disturb the widow's pensiveness."

From pensive + -ness.