Extend, draw out (8)
I believe the answer is:
lengthen
This clue is a double definition.
'extend' is the first definition.
(I know that extend is a more specific form of lengthen)
'draw out' is the second definition.
(thesaurus)
(Other definitions for lengthen that I've seen before include "Elongate" , "Spin out" , "Extend or draw out" , "increase in duration" , "Protract" .)