brethren

noun

1. (archaic, form-of, plural)plural of brother

   “The Introit over, the service is interrupted for the feast. Contrary to the festive fashion of the nobles, who all sit with their swords beside them, here, in this feast of brethren, are no arms, not even a knife.”

2. (poetic)kinsmen
3. (figuratively, plural, plural-only)The body of members, especially of a fraternal, religious or military order.
4. (plural, plural-only)Members of any congregation in the Anabaptist tradition of the Schwarzenau Brethren, practicing credobaptism and committed to nonresistance and nonviolence, some of whom may wear plain dress and shun modern technology.
5. (plural, plural-only, specifically)Members of the Church of the Brethren.

adj

1. Of or akin to; related; like

   “The principle still sounds good, but our astronomical knowledge is limited, and we haven't yet discovered any such brethren solar systems.”