Definition
To think about something worrying or upsetting for a long time. Often used when someone can't stop dwelling on a problem or bad feeling.
Example
She brooded over the argument for days.
Show translation
She kept thinking unhappily about the argument for days.
Etymology
From Old English *brōd* (noun), meaning the young of a bird, related to Middle Dutch *broeden* — "to sit on eggs and warm them." The sense of quietly sitting with something heavy on your mind evolved from the image of a hen sitting motionless on a nest, incubating. By the 16th century the verb had extended to humans lost in dark, lingering thought.
Cultural note
In literature, brooding characters — think Heathcliff in *Wuthering Heights* or Mr. Darcy — are a staple of the Romantic tradition. "Brooding" as an adjective is also widely used to describe a dark, moody atmosphere or a mysteriously intense person, so you'll often encounter it in film and book reviews.