Soldier's uniform (7)
I believe this clue is a double definition.
'soldier's' is the first definition.
(member of the regular army)
'uniform' is the second definition.
(similar in meaning)
(Other definitions for regular that I've seen before include "Soldier - uniform" , "Routine" , "Steady, in a fixed order" , "Frequent - usual" , "Even - constant" .)
(Other definitions for battledress that I've seen before include "Combat clothing" , "Perhaps camouflage" , "Combat wear" , "Military uniform" , "Combat uniform" .)