Amen - The word is related to "Emunah" in Hebrew, which means faith and/or belief. Adding "Amen" at the end of "...a blessing or a prayer demonstrates a statement of affirmation that the blessing is true and hope that the prayer will be answered." "Amen" is also a near acronym; its four letters stand for the three Hebrew words: "Aiy'l Melech Ne-eman" which mean that God is a true and faithful king.

The word Amen (Tiberian Hebrew ’Amen "So be it; truly", Standard Hebrew Amen, Arabic ’Amin) is a declaration of affirmation found in the Hebrew Bible and in the Qur'an. It has always been in use within Judaism. It has been generally adopted in Christian worship as a concluding formula for prayers and hymns. In Islam, it is the standard ending to surat al-Fatiha. (wikipedia)

A Hebrew word meaning truly, it is true. As a concluding word of prayers, it expressed assent to and acceptance of God's will. (ArchMil )

The word is related to "Emunah" in Hebrew, which means faith and/or belief. Adding "Amen" at the end of "...a blessing or a prayer demonstrates a statement of affirmation that the blessing is true and hope that the prayer will be answered." "Amen" is also a near acronym; its four letters stand for the three Hebrew words: "Aiy'l Melech Ne-eman" which mean that God is a true and faithful king. (Religious Tolerance)