loneliness
n. uncountablen. the unhappy feeling you have when you are alone and do not have any friends or people to talk to. It is different from just being alone because it feels sad or empty.
n. a state of sadness or isolation resulting from a perceived lack of social connection or companionship. Refers to the subjective emotional distress rather than the objective state of being solitary.
He felt a deep sense of loneliness after moving to the new city.
Despite being surrounded by colleagues at the office, she struggled with a persistent feeling of loneliness throughout the day.
Sociologists argue that modern urban design can inadvertently increase loneliness by reducing the spontaneous social interactions that once occurred in traditional communal spaces.
From lonely + -ness.
Uncountable in its general sense; often follows verbs like 'feel', 'suffer from', or 'overcome'.