ENGLISH
REFERENCE

brethren

n.
US //ˈbɹɛðɹən// UK //bɹˈɛðɹən// brethren
  1. 1 fellow members (n.)
    C1 Advanced Formal Literary Religion

    people who belong to the same religious or social group.

    The collective members of a fraternal, religious, or military order, emphasizing a shared bond or mission.

    Example

    The leader called upon his brethren to help those in need in the village.

    Example

    The manifesto was addressed to his brethren in the movement, urging them to remain steadfast despite the increasing political pressure.

    Usage

    Always plural; it functions as a collective noun for a specific community.
  2. 2 brothers (n.)
    C2 Proficiency Archaic Literary

    an old word for brothers, often used in a spiritual way.

    An archaic plural of brother, now restricted to religious or highly stylized literary contexts.

    Example

    The ancient text spoke of the love between brethren.

    Example

    In the solemn atmosphere of the cathedral, the monk prayed for the souls of his departed brethren.

    Teacher's tip

    Modern speakers should use 'brothers' for family members; 'brethren' is almost exclusively found in the Bible or formal lodge settings.
    Pitfall
    He has two brethren.
    He has two brothers.

    Use 'brothers' for male siblings in a family. 'Brethren' is only for members of a society or church.

Origin

From Early Modern English brethren, plural of brother, from Middle English brethren, from Middle English brethere, brether + -en (plural ending). Ultimately from Old English brōþor, brōþru (“brothers, brethren”), influenced by Old English brēþer, dative singular of brōþor (“brother”). Equivalent to brother + -en (plural ending). Compare German Brüder (“brothers, brethren”). More at brother. The vowel change (from o to e) is called umlaut.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Last updated June 20, 2026