Sentence examples for a horrible from inspiring English sources

"a horrible" is a grammatically correct phrase that can be used in written English.
It is a determiner + adjective combination, often used to describe a noun. Example: "She had a horrible nightmare last night." (In this sentence, "horrible" is describing the noun "nightmare.") Another example: "The food at that restaurant was a horrible mess." (Here, "horrible" is describing the noun "mess.").