broPronunciation: /brəʊ/Definition of bro noun informal short for brother.his baby bro (Bro.) Brother (used before a first name when referring in writing to a member of a religious order of men):Bro. Felix chiefly North American a friendly greeting or form of address:‘Yo bro!’Origin: mid 17th century: written or colloquial abbreviation of brother. Compare with Brosbro in other Oxford dictionaries Definition of bro in the US English dictionary
