(n.) A brother by the marriage of one's father with the mother of another, or of one's mother with the father of another.

auntie blood brother brethren brother bub bubba bud buddy country cousin cousin cousin once removed cousin twice removed daughter father first cousin foster brother frater grandnephew grandniece granduncle great-aunt great-uncle half brother kid brother mother nephew niece nuncle nunks nunky second cousin sis sissy sister sister-german sistern son stepbrother stepsister unc uncle uncs uterine brother