An example of something that would be described as loathsome is an offensive philosophy such as racism or bigotry.
She frequently walks a dog, a loathsome animal who fails to warm to my affection.
Carrie had looked at him as if he was some particularly loathsome slug.
Both suffered severely from the insufficient and loathsome food, and Mertz collapsed on Jan.
It's a maudlin rumination on loathsome rich kids and their disgusting, ill-mannered behavior, and their even more disgusting, ill-mannered parents.
Nature had made him mean, the smallpox had made him hideous, and his degraded habits made him loathsome.