give a bad name to (someone or something)
To tarnish the reputation of a general class of person or thing (such as an occupation) through one's poor behavior. I can't believe how little you care about your students! Boy, you give a bad name to teachers!
give a bad name to
Also, give someone or something a bad name . Spoil the reputation of, as in Late deliveries are giving the company a bad name. The use of bad name (sometimes put as ill name) dates from about 1400, and the proverb "He that hath a ill name is half hanged" was included in numerous collections from 1546 on.