Please correct me if I'm wrong: in British English, Carnival is the same as "Carnaval" in Portuguese. If you google "carnival images", you'll get an overwhelming number of Carnival festivity pictures.
However, in North American usage, "carnival" means two things:
1) the pre-Lent festival, mentioned above (PT "Carnaval"), and
2) a type of entertainment in a field or park at which people can ride on large machines and play games to win prizes. The same as "fair" (AmEN, BrEN) or "funfair"(BrEN) (PT "feira", "parque de diversões") -- Image:
https://www.visitgainesville.com/wp-content/uploads/2020/10/...Meaning #2 is more common in the US. Therefore, it's not uncommon for Brazilian expats to refer to "Brazilian CarnAval" to make sure there's no confusion:
http://google.com/search?q="brazilian carnaval"So if you are translating to or from American English, be careful so you don't mistranslate!