* Despite the sunny weather, the old man remained dour and unsmiling. (This sentence uses "dour" to describe someone's personality.)
* The dour expression on her face made it clear she was not happy with the news. (This sentence uses "dour" to describe a facial expression.)
* The dour atmosphere of the funeral home was heavy with grief. (This sentence uses "dour" to describe an atmosphere.)
You can also use "dour" to describe things like a dour outlook, a dour tone of voice, or even a dour landscape.