Line taken by the first person with wild boars (6)
I believe the answer is:
isobar
'line' is the definition.
(isobar is a kind of line)
'the first person with wild boars' is the wordplay.
'the first person' becomes 'I' ('I' is a first-person pronoun).
'with' means one lot of letters go next to another.
'wild' is an anagram indicator.
'boars' is an anagram of 'sobar'.
'i'+'sobar'='ISOBAR'
'taken by' is the link.
(Other definitions for isobar that I've seen before include "curve on map" , "It connects points of equal air pressure" , "Line in front" , "Line of equal barometric pressure on a map" , "Barometric curve" .)