brooding
adj.adj. showing that you are thinking deeply about something in a sad, serious, or worried way. It often describes a person who looks dark and mysterious.
adj. characterised by deep, often morbid or resentful, preoccupation with a particular subject. Frequently used to describe a person's facial expression or the dark, atmospheric quality of a landscape.
He sat in the corner with a brooding look on his face.
The film's brooding atmosphere is created by the constant rain and the dark, narrow streets of the city.
The protagonist is a brooding figure who spends much of the novel reflecting on his past failures while wandering the desolate moors.
Often used predicatively after linking verbs like 'look' or 'seem', or attributively to modify nouns like 'silence', 'atmosphere', or 'look'.