The word 'megahit' is correct and is commonly used in written English.
It is a noun that refers to a very successful and popular piece of media, such as a movie, song, or book. You can use 'megahit' when describing something that has achieved immense success and widespread recognition. It can also be used to highlight the magnitude of the impact or popularity of a particular work. Example: "The new Marvel movie was a megahit, breaking box office records and receiving praise from critics and audiences alike."
Dictionary
megahit
noun
A large success or hit.
synonyms
Exact(60)
http://qi.com/podcast/ Welcome to Night Vale US cult megahit presented as a radio show from the fictional titular town.
The story of South Korean rap sensation Psy's ascent to global stardom with his megahit "Gangnam Style" has now been immortalised in full colour and with appropriate dramatic flourishes in a comic book.
"Gossip Girl" has indeed become a hit, though not a megahit.
September 30 2014 October 4 4 2014 Although she is routinely associated with her husband, Tom Hanks, Wilson has plenty to show for herself, both as a producer, with the sleeper megahit "My Big Fat Greek Wedding," and as an actress, with a recurring role on "Girls".
They'd already had a megahit, and they were like, "Listen, we want to help you guys make a show you want to make".
In Spielberg's new megahit, "The Lost World: Jurassic Park," the animated dinosaurs seem in every way more genuine and less mechanical than the people... A recent "Simpsons" episode lampooned, with perfect contempt, various live-action TV genres.
This April, during a performance in Nashville, Adams, who had discussed his annoyance at being confused with the singer Bryan Adams, performed an elegant acoustic cover of that singer's 1984 megahit "Summer of '69".
Mindful, as a Hollywood executive, that a megahit allowed to slip through the fingers could result in a severance package consisting exclusively of a single crystal of anthracite, I granted Forcemeat a moment to spin his contrivance.
The sound and tepid fury of Nickelback is perhaps best summed up by the cover image on it megahit album, "Silver Side Up": an eye crying metal tears.
Under the direction of John Collins, "Arguendo" holds on to the chaos-out-of-order formula that characterized the Elevator Repair Service's improbably successful verbatim adaptations of "The Sun Also Rises," "The Sound and the Fury" and "The Great Gatsby," which was called "Gatz" and was a megahit at the Public a few years ago.
But you're a serious artist; how do you deepen and expand your career beyond this commercial megahit?
Write better and faster with AI suggestions while staying true to your unique style.
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.

Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com