Progressed (9)
(Other definitions for developed that I've seen before include "mature" , "Like film suitable for viewing" , "Grew, progressed, evolved" , "complex perhaps" , "Caught" .)
'progressed' is the definition.
('advance' can be a synonym of 'progress')
This is all the clue.
(Other definitions for advanced that I've seen before include "Proposed" , "Far on in progress or life" , "was approaching" , "Went forward like army" , "subbed" .)