lineal
adjective /ˈlɪniəl/
  /ˈlɪniəl/
 [only before noun] (formal)- coming in a direct line from an earlier or later generation of the same family as somebody
- a lineal descendant of the company’s founder
 
Oxford Collocations DictionaryLineal is used with these nouns:- descendant
 - descent
 
Word Originlate Middle English: via Old French from late Latin linealis, from linea ‘a line’.