C'est fin is french expression which means "it's the end”, “he finished”. The correct pronunciation is “ce finí” (“e” closed).
In French, "c'est" means "that is" or simply "is". It's a contracted form of "you are". “end” means finished, finished.
Ce is classified in French as adjectif demonstratif (masculine demonstrative adjective in Portuguese) and can designate "this", "this", "ess", "this", "that", which in the grammar of the Portuguese language are classified as demonstrative pronouns.
One of the uses of "c'est” is when there is a question about a certain object, place, person, etc. The singular answer must contain "c'est”. For example:
What's up? (What is it?)
C’est a musee. (It's a museum).
In the plural the expression would become "cesont”. The French verb “être” (to be, to be) is conjugated in the third person singular as “is” (is) and in the third person plural as “sont" (they are).
This French expression is often used by a person to indicate that a matter is closed and that they no longer want to talk about it. Ex: I will not buy you a car. C'est fin.
Zefini
The popular term “zefini” has its origins in the French expression “c'est fini” and is used with the same meaning. However, the pronunciation is usually with an open “e” (zephini).