• brotherlike, brotherly, fraternal
• brotherlike, brotherly, cousinly
• brotherhood, fraternity
• brotherliness, fraternity
• halfbrother, halfsister, stepbrother, stepsister
• to be of the same communion, to belong to the same communion
• foster-brother, foster-sister
• full brother, full sister
• halfbrother, halfsister, stepbrother, stepsister
• cousin german, first cousin, full cousin