quarter brother
my half-brother's half-brother
Jason and Lydia's son is Sam. Clai and Lydia's son is Will. Jason and Maureen's son is Davis. Will and Davis are quarter brothers.
three-quarter-brother
Son of a person's father with that same person's maternal aunt or son of a person's mother with that same person's paternal uncle.
My three-quarter-brother is a good person.