Answer:
If Amen is? This is not really a question but I assume that what you really mean is "What is Amen? If this is what you mean then here is your answer. Amen is a word said at the end of prayers such as "Praise be to God;Amen", it's meaning is "so be it".
When you don't know the meanings of English words it is a good idea to get an English Dictionary which is a book of words and their meanings.
Good luck in learning English!