Meaning

noun the kinship relation between a male offspring and the siblings

noun people engaged in a particular occupation

noun the feeling that men should treat one another like brothers

originFrom Middle English brotherhod, equivalent to brother + -hood, from earlier brotherhede, alteration (influenced by suffixes in -hood, -head) of Early Middle English brotherrede (“brotherhood, fraternity”), from Old English brōþorrǣden (“brotherhood, fellowship”), equivalent to brother + -red (see brotherred). More at brother, -red. Piecewise doublet of friarhood.

Etymology from Wiktionary, CC BY-SA 3.0