patrilineal (adj.)

word-forming element used in terms describing kinship of the father or the paternal line, from Latin patri-, combining form of pater (see father (n.)).

late 14c., "resembling a line," from Old French lineal "pertaining to a line" (14c.), from Late Latin linealis "pertaining to a line," from linea "a string, line, thread" (see line (n.)). Compare linear. Related: Lineally.