The state or characteristic of being wistful.(noun)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "wistfulness" in a sentence
"He was several years younger than his partner, not more than twenty-six, and there was a certain wistfulness in his face that comes into the faces of men when they yearn vainly for the things they have been long denied."
"We are in the realm not of logic but of wistfulness, and I must maintain that wistfulness is a respectable, serious condition."
"This wistfulness is charming but self-deceptive: Schlesinger might have written not just more books but better ones (as we know from the quality of The Age of Jackson and The Disuniting of America) if he had not squandered so much time and energy being a compulsive socialite and an insecure valet du pouvoir."