solitariness
noun /ˈsɒlətrinəs/
  /ˈsɑːləterinəs/
[uncountable]- the fact of being alone, without other people synonym loneliness (2)
- She loved family life and dreaded the solitariness of her new position.
 
 - pleasure in being alone; the fact of frequently spending time alone
- Even as a boy he was given to solitariness.