Drew together to study pamphlet with editor (10)
I believe the answer is:
contracted
'drew together' is the definition.
('contract' can be a synonym of 'draw together')
'study pamphlet with editor' is the wordplay.
'study' becomes 'con' (con can mean to study).
'pamphlet' becomes 'tract' (synonyms).
'with' is a charade indicator (letters next to each other).
'editor' becomes 'ed' (abbreviation).
'con'+'tract'+'ed'='CONTRACTED'
'to' acts as a link.
(Other definitions for contracted that I've seen before include "Formally agreed; shrank" , "Got shorter" .)