Other forms: brothers
Your brother is a boy or man with the same parents as you. My older brother, two brothers, his brother-in-law.
Half-brother shares one parent, stepbrother shares none but is family by marriage. The plural is brothers, and the old plural brethren survives only in religious and formal use. Brother is also a title for a monk, and a form of address among members of a union, a church or a movement. Note brotherly, brotherhood, and big brother, which since Orwell has meant surveillance as often as a sibling.
1nounbrotherA boy or man with the same parents as you.~94%
“Her brother is three years younger and about a foot taller.”
2nounmemberA member of the same group or order.~6%
“The brothers have run the school since 1871.”
Shares are an estimate: a language model read 18 sentences found in the wild and placed 18 of them on a sense — a count of our sample, not a measurement of English.
brother is a relative or fellow member.
Old English brothor descends from Proto-Indo-European bhrater, and it survives across the whole family: Latin frater, Greek phrater, Sanskrit bhratar. Fraternal, friar and brother are the same word arriving by three different routes.
Proto-Indo-European
*bʰréh₂tēr
Middle English
brother
English, today
brother
From Middle English brother. Middle English brother, broþer, from Old English brōþor, brōðer, from Proto-West Germanic brōþer, from Proto-Germanic brōþēr (“brother”), from Proto-Indo-European bʰréh₂tēr (“brother”). a doublet of bhai and bru and frater and friar and pal and vai. 2
Etymology from Wiktionary, CC BY-SA