The adjective gothic describes something that is characterized by mystery, horror, and gloom — especially in literature.
Gothic literature combines the genres of romance and horror. Some famous writers of Gothic fiction include Charlotte Bronte, Mary Shelley and Edgar Allan Poe. Nowadays, though, if you refer to someone as "goth," you are not saying they write a good ghost story; you are commenting on their pale makeup, black fingernail polish and Victorian fashion. Gothic can also describe something barbaric, rude, and unenlightened as if from medieval times. This use of the word is usually capitalized. The word is from the Goths, a Germanic people who invaded the Roman Empire.