Queue long time for descent (7)
I believe the answer is:
lineage
'queue' is the definition.
(thesaurus)
'long time for descent' is the wordplay.
'long time' becomes 'age' ('age' can be a synonym of 'long time').
'for' says to put letters next to each other (I've seen this in other clues).
'descent' becomes 'line' ('line' can be a synonym of 'descent').
'age' after 'line' is 'LINEAGE'.
(Other definitions for lineage that I've seen before include "Descent (from an ancestor)" , "Descent from ancestors" , "Ancestry, sequence of descendants" , "Genealogy" , "Stock" .)