1. Of brother; members of the same profession, society, or persuasion.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• brethern,
• bretheren,
• bretheran,
• brothres,
• breathen,
• brothren,
• brotheren,
• brethen,
• brothre,
• bredren,
• breathre,
• breathren,
• brethrin,
• brethrens,
• bretherin,
• breatheren,
• brehtren,
• bretherens,
• breteren,
• pyrethren

• breathed,
• rerun,
• breeder,
• breather,
• barren,
• breathe,
• Bret Harte,
• brother,
• breathing,
• Bothering,
• reran,
• broth,
• breathes,
• breath.

The adjective form of the word "brethren" is "brotherly".

The plural of the "brethren" can be the "brethren".

The singular of the "brethren" can be the "brethren".