Definition from Wiktionary, the free dictionary
patrilineage (plural patrilineages)
- A group of descendants related through a common male lineage.
- A group of male and female descendants of a male ancestor, each of whom is related to the common ancestor through male forebears. Library of Congress / Federal Research Division / Country Studies ... 
- 1979 "By 1770, the Xhosa branch of the Nguni-speakers were organised at three levels: patrilineages, consisting the descendants of a known common ancestor; patriclans, composed of a number of lineages, all claiming descent from a putative common ancestor; and chiefdoms which were political units, each occupying a certian area under a chief. The shaping of South African Society 1652 - 1820. Eds. Richard Elphic & Hermann Giliommee. Longman p. 294.