The phrase "unannounced appearance" is correct and can be used in written English.
It refers to someone arriving or showing up without prior notice or announcement. It can be used in various scenarios, such as unexpected guest appearances, surprise visits, or unexpected attendance at an event. Here is an example sentence: "Much to everyone's surprise, the CEO made an unannounced appearance at the company's annual meeting, causing a buzz of excitement among the employees."
Gov. Jerry Brown made an unannounced appearance at the event.
My brain processed the question, the unannounced appearance and its possible meaning.
There was an unannounced appearance by Jaime Pressly, an actress whose credits include "Piñata: Survival Island".
Photograph: smileycaprice/Twitter 12.02pm BST Aphex Twin made a rare, and unannounced, appearance at the Common in the early hours.
Beyoncé also made an unannounced appearance, leading a rapt audience of fans and music executives through a soaring singalong of her latest single XO.
Former president Bill Clinton made an unannounced appearance in Detroit on Wednesday night to meet privately with black ministers, the city's mayor and other local leaders.
Chappelle Returns and Hits the Clubs Dave Chappelle, left, missing in action for more than a month, made surprising unannounced appearances at two comedy clubs in Los Angeles late Wednesday night, saying that he had just arrived in town and felt like performing, The Associated Press reported.
Lately, celebrities from Bill Clinton to LeBron James have been making unannounced appearances at "regular" people's weddings.
While it has been screened in numerous film festivals and museums, its from these random and unannounced appearances on late night European television that the majority of people have seen VIDEO 50; in fragments, without any way of figuring out what they were looking at.
The outbreak was compared to Mariah Carey's unannounced 2001 appearance on TRL, when she handed out popsicles to the show's audience and performed a "striptease", while some fans noted Usher's speech as evidence that Foster was being controlling of Usher.
Earlier in the night, long before Jay Electronica took the stage, Big K.R.I.T. made an unannounced guest appearance at the Highline.
