›[C]something official that must be done before something else can happen or be done: It is essential to observe all the formalities when setting up a business.complete/go through the formalities (of sth)This should be a means of injecting share capital into a company without going through the formalities of a share issue.Approval of the documents is a legal formality.
›[C,usually singular]something that must be done but that is unlikely to affect an agreement that has already been made: little more than/only/merely a formalityThere are still some details to be sorted out, but I believe it's only a formality.Background checks often are a mere formality in the hiring process.
›[U]formal writing, behaviour, etc. that is suitable in important or official situations: The bank says its business overdrafts are arranged with a minimum of formality and fuss.