The very capaciousness of the idea meant that agreement on fundamentals was unnecessary. His unselfishness gave him great intellectual roominess.
source: WordNet 3.0
spatial largeness and extensiveness (especially inside a building)
The capaciousness of Santa's bag astounded the child. Roominess in this size car is always a compromise. His new office lacked the spaciousness that he had become accustomed to.
source: WordNet 3.0
The quality or state of being roomy; spaciousness; as, the roominess of a hall.
