Injured eagle in descent (7)
I believe the answer is:
lineage
'descent' is the definition.
(I know that descent can be written as lineage)
'injured eagle in' is the wordplay.
'injured' indicates an anagram.
'eagle'+'in'='eaglein'
'eaglein' anagrammed gives 'LINEAGE'.
(Other definitions for lineage that I've seen before include "The strain" , "Descent from ancestors" , "Ancestral line as seen in eagle" , "Direct descent" , "Family descent" .)