Amish \Am"ish\, n. sing. & pl. [Written also {Omish}.] (Eccl. Hist.) The Amish Mennonites. [Webster 1913 Suppl.]
Amish \Am"ish\, a. [Written also {Omish}.] (Eccl. Hist.) Of, pertaining to, or designating, the followers of Jacob Amman, a strict Mennonite of the 17th century, who even proscribed the use of buttons and shaving as "worldly conformity". There are several branches of Amish Mennonites in the United States. A branch having particularly strict adherence to the Amish principles are called {Old Order Amish} [Webster 1913 Suppl. +PJC]