From Longman Dictionary of Contemporary Englishso-and-soˈso-and-so noun 1 [uncountable]NAME OF A PERSON used to refer to a particular person or thing when you do not give a specific name → such and such I’d find myself thinking, ‘I wonder what so-and-so is doing?’2 [countable]NAME OF A PERSON a very unpleasant or unreasonable person – used when you want to avoid using a swear word Peter can be a real so-and-so at times.
Examples from the Corpus
so-and-so• They're always gossiping about so-and-so having an affair with so-and-so.• He'd say, "Lula, let's do so-and-so, " and expect me to do it.• The paper is full of stories about how so-and-so violated this or that law.• Johnson was a mean old so-and-so. 