Dream girl heads section (8)
I believe the answer is:
division
'section' is the definition.
('division' can be a synonym of 'section')
'dream girl heads' is the wordplay.
'dream' becomes 'vision' (I've seen this before).
'girl' becomes 'di'.
'heads' says to put letters next to each other (some letters go ahead of others).
'vision' after 'di' is 'DIVISION'.
(Other definitions for division that I've seen before include "Group of football teams" , "Part of a whole, a section" , "Formal vote in Parliament" , "Discord, split" , "Large army unit" .)