If the Hebrew or (the transliterated) Greek “Amen” (as part of a prayer) is not transliterated it can also be translated into expressions such as “that is just the way it is” (Huichol), “that’s it” (Shilluk), “may it be thus” (Tzeltal) (source: Bratcher / Nida), or “Let those things thus be” (Kituba) (source: Donald Deer in The Bible Translator 1973, p. 207ff. ).
In Mairasi the translation is aniaut aug or “it’s a tuberful dig.” The preface to Enggavoter 2004 explains: “Truth is like a tuber [sweet potatoes, taro, cassava, yams]. We Mairasi have tubers as our standard food. The leaves are visible above ground. But we planted the plant so that it would produce tubers, but those are beneath the ground. So the vocabulary about ‘truth’ and ‘produce’ or ‘fruit’ is based on words for ‘tubers.’ For example: the word for ‘Amen’ ‘it’s a tuberful dig’ [also used for ‘verily’ or ‘definitely’] has its story like this: We see the leaves of the sweet potato but we do not know: the question is ‘Are there tubers or not?.’ So we dig then we see tubers. Therefore we say that ani ‘dig’ was aut ‘with tubers,’ which is ‘Aniaut!‘ ‘Definitely true!'”
In Huba it is translated as Aɗǝmja or “let it be so.” David Frank (in this blog post) explains: “Whenever there were persistent problems such as a drought, or a rash of sickness or death, the king (or his religious advisor) would set aside a day and call on everyone to prepare food, such as the traditional mash made from sorghum, or perhaps even goat. The food had to be put together outside. The king or his religious advisor would give an address stating what the problem was and what they were doing about it. Then an elder representing the people would take a handful of that food and throw it, probably repeating that action several times, until it was considered to be enough to atone for all the misfortune they had been having. With this action he was ‘shooting (or casting off) misfortune’ to restore well-being to his people. As he threw the food, he would say that this is to remove the misfortune that had fallen on his people, and everybody would respond by saying aɗǝmja, ‘let it be so.’ People could eat some of this food, but they could not bring the food into their houses, because that would mean that they were bringing misfortune into their house. There is still a minority of people in this linguistic and cultural group that practices the traditional religion, but the shooting of misfortune is no longer practiced, and the term ‘shoot misfortune’ is used now in Bible translation to refer to offering a sacrifice. Aɗǝmja is how they translate ‘amen.'”
“Amen” in American Sign Language (source )