n.a person who has the right to be considered legally a British citizen (by virtue of the birth of a parent or grandparent)
英汉双解大词典
patrial/ˈpeɪtrɪəl/
1.
N（名词）
(in Britain formerly) a person having by statute the right of abode in the United Kingdom, and so not subject to immigration control (英国曾经的)有英国居留权的人; 所以不受入境检查的影响