To be consistent, pull up in the rear (7)
I believe the answer is:
regular
'to be consistent' is the definition.
(thesaurus)
'pull up in the rear' is the wordplay.
'pull' becomes 'lug' (I've seen this before).
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'in the' means one lot of letters goes inside another.
'lug' reversed gives 'gul'.
'gul' placed within 'rear' is 'REGULAR'.
(Other definitions for regular that I've seen before include "Recurring at short uniform intervals" , "Soldier - uniform" , "fighter" , "Predictable" , "Usual, customary" .)