Someone you share a line with (8)
I believe the answer is:
ancestor
'someone' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'share a line with' is the wordplay.
I cannot quite see how this works, but
'a' could be 'an' and 'an' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'you' is the link.
Can you help me to learn more?
(Other definitions for ancestor that I've seen before include "Antecedent, forebear" , "Predecessor" , "Old member of the family -no traces (anag)" , "Forefather" , "not being of the modern generation" .)