What is Undesirable ?
Undesirable is adj 1. not wanted It’s highly undesirable that they should build a factory in the national park. 2. not pleasant Taking the medicine produces no undesirable effects. noun a person who is not wanted, who is considered a bad influ- ence We are tightening the immigration law to keep undesirables out of the country.
source: Easier English, Student Dictionary Upper Intermediate Level