"Formal gatherings" refers to formal events or occasions where people gather together in a structured and proper setting, usually following a set of rules and etiquette.
Sentences with «formal gatherings»
Did you know that you can dress up a t - shirt dress for formal gatherings too? (creativefashionglee.com)
One reservation, though: if you are having a more formal gathering I would omit this recipe because it doesn't look very chic on the table. (epicurious.com)