1844, American English, from the name of Jacob Amman, 17c. Swiss Mennonite preacher who founded the sect. Originally spelled Omish, which reflects the pronunciation in Pennsylvania German dialect. As a noun, by 1884.
A group of Protestants who broke away from the Mennonites in the seventeenth century. The Amish live in close communities, farm for a living, and do without many modern conveniences, such as telephones, automobiles, and tractor-drawn plows.
Note: Some of the Pennsylvania Dutch are Amish.