Lined up, dealing in disguise (7)
I believe the answer is:
aligned
'lined up' is the definition.
('align' can be a synonym of 'line up')
'dealing in disguise' is the wordplay.
'in disguise' indicates anagramming the letters.
'dealing' is an anagram of 'ALIGNED'.
(Other definitions for aligned that I've seen before include "Put straight" , "made to toe the line" , "Arranged in rows" , "joined forces" , "Brought into the correct relationship (with)" .)