No, retention has a really limited use in English, and I would kind of avoid its use as a non-native speaker of English. It just means to keep something, coming from the commonly used verb "to retain". But retention as a noun is uncommonly used, or only has a limited use. A couple of examples come to mind. You could say "she has fluid rentention" , a medical term for edema. That's okay. Or you can say "his rentention" (i.e. his memory) is terrible". So, retention can mean memory too. You might get away with using the word in ways not referring to the human body, but they sound a little odd to me. I'm pretty sure you could say, for example, "his continued retention of the money is unlawful." That works. But frankly it's hard to come up with many examples that are appropriate for use of the word. Hence, I'd advise being very careful in using the word, or avoid it altogether and select more commonly used alternatives.