The stigmatizing of adults who are single. It includes negative stereotyping of singles and discrimination of singles. The word singlism is analagous to terms such as racism and sexism.
In the interview I was directly asked by the owner of the company if I was single or married, I told him
I was single. He made it a point to acknowledge that the philosophy of the company was to hire married people. I was not offered a position although I had all the qualifications, this is an obvious case of Singlism.