Any crest altered in line of descent? (8)
I believe the answer is:
ancestry
'line of descent?' is the definition.
(synonyms)
'any crest altered in' is the wordplay.
'altered' indicates an anagram.
'in' indicates putting letters inside.
'crest' with letters rearranged gives 'cestr'.
'any' enclosing 'cestr' is 'ANCESTRY'.
(Other definitions for ancestry that I've seen before include "Line of descendants" , "Lineage" , "Any crest (anag.)" , "Family tree" , "Genealogy" .)