Regalia is clothing worn for formal functions by people who will be in the public eye. If you see Miss America at the grocery store, you might not recognize her because she's not wearing her pageant regalia.
Regalia looks like regal and in fact, can refer to things owned by members of royalty that convey their official positions. Crowns, sashes, scepters, tiaras? Regalia. The prince's riding boots and the duchess's bath robes? Nope. Technically, regalia is a plural word, from Latin (the singular would be regalis) but it can be used with a singular or plural verb: Here is Queen Elizabeth's regalia. Her regalia are exquisite.
