What is "omish"

Amish \Am"ish\, n. sing. & pl. [Written also Omish.] (Eccl. Hist.) The Amish Mennonites.

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