Old English, from Late Latin amen, from Ecclesiastical Greek amen, from Hebrew amen “truth,” used adverbially as an expression of agreement (as in Deuteronomy xxvii.26, I Kings i.36), from Semitic root a-m-n “to be trustworthy, confirm, support.”
Compare similar use of Modern English certainly, absolutely. Used in Old English only at the end of Gospels, otherwise translated as Soðlic! or Swa hit ys, or Sy! As an expression of concurrence after prayers, it is recorded from early 13c.
“hawk-headed sovereign sun god of Egyptian mythology,” from Egyptian R’ “sun, day.”
late 14c., “quality of being pleasant or agreeable,” from Latin amoenitatem (nominative amoenitas) “delightfulness, pleasantness,” from amoenus “pleasant,” which is perhaps related to amare “to love”
early 13c., “betterment, improvement;” c. 1300, of persons, “correction, reformation,” from Old French amendement “rectification, correction; advancement, improvement,” from amender (see amend). Sense expanded to include “correction of error in a legal process” (c. 1600) and “alteration of a writ or bill” to remove its faults (1690s).