Hi Craig...simply put "Amen" means "So be it"
Here's a deeper explanation...
The word Amen (pronounced /ˌɑːˈmɛn/ or /ˌeɪˈmɛn/; Hebrew: אָמֵן, Modern Amen Tiberian ’Amen ; Arabic: آمين, ’Āmīn ; "So be it; truly") is a declaration of affirmation[1][2] found in the Hebrew Bible and New Testament. Its use in Judaism dates back to its earliest texts.[3] It has been generally adopted in Christian worship as a concluding word for prayers and hymns.[2] In Islam, it is the standard ending to Dua (supplication). Common English translations of the word amen include: "Verily", "Truly", "So say we all", "So be it", and "Let it be." It can also be used colloquially to express strong agreement,[2] as in, for instance, amen to that.[4]