The definition of a cobber is Australian slang for a friend.(noun)
An example of a cobber is someone a person has been close to his whole life.
See cobber in Webster's New World College Dictionary
Origin: prob. < Heb (via Yiddish) chaver, comrade
See cobber in American Heritage Dictionary 4
Origin: Possibly from dialectal cob, to take a liking to.
Learn more about cobber